debugfs.c (do_open_filesys): Fix obvious uninitialized variable
	buglet.

diff --git a/debugfs/debugfs.c b/debugfs/debugfs.c
index dab49d4..e4a8b8f 100644
--- a/debugfs/debugfs.c
+++ b/debugfs/debugfs.c
@@ -124,7 +124,7 @@
 	blk_t	superblock = 0;
 	blk_t	blocksize = 0;
 	int	open_flags = 0;
-	char	*data_filename;
+	char	*data_filename = 0;
 	
 	reset_getopt();
 	while ((c = getopt (argc, argv, "iwfcb:s:d:")) != EOF) {