audit: remove unnecessary assignment in audit_dupe_lsm_field()

The ret variable is assigned when it does not need to be defined, as it
has already been assigned before use.
Signed-off-by: Li zeming <zeming@nfschina.com>
[PM: rewrite subject line]
Signed-off-by: Paul Moore <paul@paul-moore.com>

kernel/auditfilter.c

@@ -788,7 +788,7 @@ static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 static inline int audit_dupe_lsm_field(struct audit_field *df,
 					   struct audit_field *sf)
 {
-	int ret = 0;
+	int ret;
 	char *lsm_str;
 
 	/* our own copy of lsm_str */