cifs: fix uninitialized pointer in error case in dfs_cache_get_tgt_share

Set default value of ppath to null.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

fs/cifs/dfs_cache.c

@@ -1267,7 +1267,8 @@ int dfs_cache_get_tgt_share(char *path, const struct dfs_cache_tgt_iterator *it,
 			    char **prefix)
 {
 	char sep;
-	char *target_share, *ppath;
+	char *target_share;
+	char *ppath = NULL;
 	const char *target_ppath, *dfsref_ppath;
 	size_t target_pplen, dfsref_pplen;
 	size_t len, c;