vlm: Fix a warning about a non initialized pointer use, and fix a potential...

vlm: Fix a warning about a non initialized pointer use, and fix a potential free() of a random pointer.

src/input/vlm.c

@@ -670,7 +670,7 @@ static int ExecuteExport( vlm_t *p_vlm, vlm_message_t **pp_status )
 static int ExecuteSave( vlm_t *p_vlm, const char *psz_file, vlm_message_t **pp_status )
 {
     FILE *f = utf8_fopen( psz_file, "wt" );
-    char *psz_save;
+    char *psz_save = NULL;
 
     if( !f )
         goto error;