s390/ipl: only print boot menu error if -boot menu=on was specified

It is possible that certain QEMU configurations may not
create an IPLB (such as when -kernel is provided). In
this case, a misleading error message will be printed
stating that the "boot menu is not supported for this
device type".

To amend this, only print this message iff boot menu=on
was provided on the commandline. Otherwise, return silently.

While we're at it, remove trailing periods from error
messages.

Signed-off-by: Collin L. Walling <walling@linux.vnet.ibm.com>
Message-Id: <1519760121-24594-1-git-send-email-walling@linux.vnet.ibm.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Cornelia Huck <cohuck@redhat.com>

hw/s390x/ipl.c

@@ -234,7 +234,7 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
     if (!get_boot_device(0)) {
         if (boot_menu) {
             error_report("boot menu requires a bootindex to be specified for "
-                         "the IPL device.");
+                         "the IPL device");
         }
         return;
     }
@@ -250,7 +250,9 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
     case S390_IPL_TYPE_QEMU_SCSI:
         break;
     default:
-        error_report("boot menu is not supported for this device type.");
+        if (boot_menu) {
+            error_report("boot menu is not supported for this device type");
+        }
         return;
     }
 
@@ -263,13 +265,13 @@ static void s390_ipl_set_boot_menu(S390IPLState *ipl)
     tmp = qemu_opt_get(opts, "splash-time");
 
     if (tmp && qemu_strtoul(tmp, NULL, 10, &splash_time)) {
-        error_report("splash-time is invalid, forcing it to 0.");
+        error_report("splash-time is invalid, forcing it to 0");
         *timeout = 0;
         return;
     }
 
     if (splash_time > 0xffffffff) {
-        error_report("splash-time is too large, forcing it to max value.");
+        error_report("splash-time is too large, forcing it to max value");
         *timeout = 0xffffffff;
         return;
     }