ra: fix undefined behavior on error (#2452)

flb_ra_parser_destroy(rp) may attempt to free uninitialized key->subkeys
when key->name failed to allocate.

Signed-off-by: Zero King <[email protected]>

Author: l2dy

src/record_accessor/flb_ra_parser.c

@@ -224,12 +224,12 @@ struct flb_ra_parser *flb_ra_parser_string_create(char *str, int len)
         flb_ra_parser_destroy(rp);
         return NULL;
     }
+    rp->key->subkeys = NULL;
     rp->key->name = flb_sds_create_len(str, len);
     if (!rp->key->name) {
         flb_ra_parser_destroy(rp);
         return NULL;
     }
-    rp->key->subkeys = NULL;
 
     return rp;
 }