rfcomm-tester: Fix crash on test-basic

This fixes to following trace caused by not initializing data->io:

AddressSanitizer:DEADLYSIGNAL
=================================================================
ERROR: AddressSanitizer: SEGV on unknown address
(pc 0x7f199c3a01c9 bp 0x7ffc26624a10 sp 0x7ffc26624a00 T0)
The signal is caused by a READ memory access.
Hint: this fault was caused by a dereference of a high value address
(see register values below).  Disassemble the provided pc to learn .
    #0 0x7f199c3a01c9 in g_io_channel_unref (/lib64/libglib-2.0.so.0+0x4d1c9)
    #1 0x5565f82fcece in test_post_teardown tools/rfcomm-tester.c:205
    #2 0x5565f83939b3 in teardown_callback src/shared/tester.c:434

tools/rfcomm-tester.c

@@ -30,6 +30,7 @@
 
 #include "src/shared/tester.h"
 #include "src/shared/mgmt.h"
+#include "src/shared/util.h"
 
 struct test_data {
 	struct mgmt *mgmt;
@@ -815,9 +816,7 @@ static void test_server(const void *test_data)
 #define test_rfcomm(name, data, setup, func) \
 	do { \
 		struct test_data *user; \
-		user = malloc(sizeof(struct test_data)); \
-		if (!user) \
-			break; \
+		user = new0(struct test_data, 1); \
 		user->hciemu_type = HCIEMU_TYPE_BREDRLE52; \
 		user->test_data = data; \
 		user->io_id = 0; \