utils/db_berkeley: fixed unused var

kambdb_recover.c: In function 'load_metadata_columns':
kambdb_recover.c:819:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
  819 |  int ret,n,len;
      |      ^~~

(cherry picked from commit 792261b)

utils/db_berkeley/kambdb_recover.c

@@ -816,11 +816,11 @@ table_p create_table(char *_s)
 */
 int load_metadata_columns(table_p _tp, char* line)
 {
-	int ret,n,len;
+	int n,len;
 	char *s = NULL;
 	char cn[64], ct[16];
 	column_p col;
-	ret = n = len = 0;
+	n = len = 0;
 
 	if(!_tp) return -1;
 	if(_tp->ncols!=0) return 0;