fuse: fix large stack use

gcc 4.4 warns about:
  fs/fuse/dev.c: In function ‘fuse_notify_inval_entry’:
  fs/fuse/dev.c:925: warning: the frame size of 1060 bytes is larger than 1024 bytes

The problem is we declare two structures and a large array on the stack,
I move the array alway from the stack and allocate memory for it dynamically.
Signed-off-by: NFang Wenqi <antonf@turbolinux.com.cn>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>

fs/fuse/dev.c

@@ -881,10 +881,15 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
 				   struct fuse_copy_state *cs)
 {
 	struct fuse_notify_inval_entry_out outarg;
-	int err = -EINVAL;
-	char buf[FUSE_NAME_MAX+1];
+	int err = -ENOMEM;
+	char *buf;
 	struct qstr name;
 
+	buf = kzalloc(FUSE_NAME_MAX + 1, GFP_KERNEL);
+	if (!buf)
+		goto err;
+
+	err = -EINVAL;
 	if (size < sizeof(outarg))
 		goto err;
 
@@ -910,9 +915,11 @@ static int fuse_notify_inval_entry(struct fuse_conn *fc, unsigned int size,
 	if (fc->sb)
 		err = fuse_reverse_inval_entry(fc->sb, outarg.parent, &name);
 	up_read(&fc->killsb);
+	kfree(buf);
 	return err;
 
 err:
+	kfree(buf);
 	fuse_copy_finish(cs);
 	return err;
 }