machine: fix a memory leak when showing multiple images

+ machinectl image-status container1 container1 container0 container1 container2 container3 container4
 =================================================================
 ==1354==ERROR: LeakSanitizer: detected memory leaks
 Direct leak of 4704 byte(s) in 6 object(s) allocated from:
     #0 0x7fc3670ba097 in calloc (/lib64/libasan.so.8+0xba097)
     #1 0x7fc365e91e8e in message_from_header ../src/libsystemd/sd-bus/bus-message.c:372
     #2 0x7fc365e92dfd in bus_message_from_malloc ../src/libsystemd/sd-bus/bus-message.c:421
     #3 0x7fc365f089a8 in bus_socket_make_message ../src/libsystemd/sd-bus/bus-socket.c:1165
     #4 0x7fc365f0affe in bus_socket_read_message ../src/libsystemd/sd-bus/bus-socket.c:1294
     #5 0x7fc365f2db71 in bus_read_message ../src/libsystemd/sd-bus/sd-bus.c:2082
     #6 0x7fc365f33352 in sd_bus_call ../src/libsystemd/sd-bus/sd-bus.c:2483
     #7 0x7fc365e4da61 in sd_bus_call_methodv ../src/libsystemd/sd-bus/bus-convenience.c:183
     #8 0x7fc3658789e8 in bus_call_method ../src/shared/bus-locator.c:109
     #9 0x413b76 in show_image ../src/machine/machinectl.c:1014
     #10 0x7fc365c5c8cf in dispatch_verb ../src/shared/verbs.c:103
     #11 0x42e992 in machinectl_main ../src/machine/machinectl.c:2981
     #12 0x42ebbd in run ../src/machine/machinectl.c:3006
     #13 0x42ece3 in main ../src/machine/machinectl.c:3009
     #14 0x7fc36444a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)
 Indirect leak of 666 byte(s) in 6 object(s) allocated from:
     #0 0x7fc3670b95b5 in __interceptor_realloc.part.0 (/lib64/libasan.so.8+0xb95b5)
     #1 0x7fc365f09822 in bus_socket_read_message ../src/libsystemd/sd-bus/bus-socket.c:1214
     #2 0x7fc365f2db71 in bus_read_message ../src/libsystemd/sd-bus/sd-bus.c:2082
     #3 0x7fc365f33352 in sd_bus_call ../src/libsystemd/sd-bus/sd-bus.c:2483
     #4 0x7fc365e4da61 in sd_bus_call_methodv ../src/libsystemd/sd-bus/bus-convenience.c:183
     #5 0x7fc3658789e8 in bus_call_method ../src/shared/bus-locator.c:109
     #6 0x413b76 in show_image ../src/machine/machinectl.c:1014
     #7 0x7fc365c5c8cf in dispatch_verb ../src/shared/verbs.c:103
     #8 0x42e992 in machinectl_main ../src/machine/machinectl.c:2981
     #9 0x42ebbd in run ../src/machine/machinectl.c:3006
     #10 0x42ece3 in main ../src/machine/machinectl.c:3009
     #11 0x7fc36444a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)
 Indirect leak of 12 byte(s) in 6 object(s) allocated from:
     #0 0x7fc36707243b in strdup (/lib64/libasan.so.8+0x7243b)
     #1 0x7fc365ec1543 in message_parse_fields ../src/libsystemd/sd-bus/bus-message.c:4125
     #2 0x7fc365e93586 in bus_message_from_malloc ../src/libsystemd/sd-bus/bus-message.c:443
     #3 0x7fc365f089a8 in bus_socket_make_message ../src/libsystemd/sd-bus/bus-socket.c:1165
     #4 0x7fc365f0affe in bus_socket_read_message ../src/libsystemd/sd-bus/bus-socket.c:1294
     #5 0x7fc365f2db71 in bus_read_message ../src/libsystemd/sd-bus/sd-bus.c:2082
     #6 0x7fc365f33352 in sd_bus_call ../src/libsystemd/sd-bus/sd-bus.c:2483
     #7 0x7fc365e4da61 in sd_bus_call_methodv ../src/libsystemd/sd-bus/bus-convenience.c:183
     #8 0x7fc3658789e8 in bus_call_method ../src/shared/bus-locator.c:109
     #9 0x413b76 in show_image ../src/machine/machinectl.c:1014
     #10 0x7fc365c5c8cf in dispatch_verb ../src/shared/verbs.c:103
     #11 0x42e992 in machinectl_main ../src/machine/machinectl.c:2981
     #12 0x42ebbd in run ../src/machine/machinectl.c:3006
     #13 0x42ece3 in main ../src/machine/machinectl.c:3009
     #14 0x7fc36444a50f in __libc_start_call_main (/lib64/libc.so.6+0x2750f)
 SUMMARY: AddressSanitizer: 5382 byte(s) leaked in 18 allocation(s).

src/machine/machinectl.c

@@ -984,9 +984,7 @@ static int show_image_properties(sd_bus *bus, const char *path, bool *new_line)
 }
 
 static int show_image(int argc, char *argv[], void *userdata) {
-
         _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
-        _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
         bool properties, new_line = false;
         sd_bus *bus = ASSERT_PTR(userdata);
         int r = 0;
@@ -1009,6 +1007,7 @@ static int show_image(int argc, char *argv[], void *userdata) {
         }
 
         for (int i = 1; i < argc; i++) {
+                _cleanup_(sd_bus_message_unrefp) sd_bus_message *reply = NULL;
                 const char *path = NULL;
 
                 r = bus_call_method(bus, bus_machine_mgr, "GetImage", &error, &reply, "s", argv[i]);