fuse: fix NULL deref in fuse_file_alloc()

ff is set to NULL and then dereferenced on line 65.  Compile tested only.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: stable@kernel.org
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index e816264..d9fdb7c 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -54,7 +54,7 @@
 		ff->reserved_req = fuse_request_alloc();
 		if (!ff->reserved_req) {
 			kfree(ff);
-			ff = NULL;
+			return NULL;
 		} else {
 			INIT_LIST_HEAD(&ff->write_entry);
 			atomic_set(&ff->count, 0);