call-barring: Quiet GCC warning

  CC       src/call-barring.o
In function ‘cb_lock_property_lookup’,
    inlined from ‘cb_set_property’ at src/call-barring.c:854:7:
src/call-barring.c:776:18: error: ‘len’ may be used uninitialized [-Werror=maybe-uninitialized]
  776 |         property += len;
      |         ~~~~~~~~~^~~~~~
src/call-barring.c: In function ‘cb_set_property’:
src/call-barring.c:759:16: note: ‘len’ was declared here
  759 |         size_t len;
      |                ^~~

1 files changed, 3 insertions, 3 deletions

diff --git a/src/call-barring.c b/src/call-barring.c
index 845cbc38..7bd547c9 100644
--- a/src/call-barring.c
+++ b/src/call-barring.c
@@ -766,15 +766,15 @@ static gboolean cb_lock_property_lookup(const char *property, const char *value,
 		prefix = bearer_class_to_string(i);
 		len = strlen(prefix);
 
-		if (!strncmp(property, prefix, len))
+		if (!strncmp(property, prefix, len)) {
+			property += len;
 			break;
+		}
 	}
 
 	if (i > BEARER_CLASS_PAD)
 		return FALSE;
 
-	property += len;
-
 	if (!strcmp(property, "Outgoing")) {
 		start = CB_OUTGOING_START;
 		end = CB_OUTGOING_END;