ubifsmount fails due to not initialized list

ubifsmount is not working and causes an access with
a pointer set to zero because the ubifs_fs_type
is not initialized correctly.

Signed-off-by: Stefano Babic <sbabic@denx.de>
Signed-off-by: Stefan Roese <sr@denx.de>

fs/ubifs/super.c

@@ -1178,6 +1178,7 @@ int ubifs_mount(char *vol_name)
 		ubifs_umount(ubifs_sb->s_fs_info);
 
 	INIT_LIST_HEAD(&ubifs_infos);
+	INIT_LIST_HEAD(&ubifs_fs_type.fs_supers);
 
 	/*
 	 * Mount in read-only mode