f2fs: move mnt_want_write_file after range check

This patch move mnt_want_write_file after range check,
it's needless to check arguments with it.
Signed-off-by: NYunlei He <heyunlei@huawei.com>
Reviewed-by: NChao Yu <yuchao0@huawei.com>
Signed-off-by: NJaegeuk Kim <jaegeuk@kernel.org>

fs/f2fs/file.c

@@ -2061,15 +2061,15 @@ static int f2fs_ioc_gc_range(struct file *filp, unsigned long arg)
 	if (f2fs_readonly(sbi->sb))
 		return -EROFS;
 
+	end = range.start + range.len;
+	if (range.start < MAIN_BLKADDR(sbi) || end >= MAX_BLKADDR(sbi)) {
+		return -EINVAL;
+	}
+
 	ret = mnt_want_write_file(filp);
 	if (ret)
 		return ret;
 
-	end = range.start + range.len;
-	if (range.start < MAIN_BLKADDR(sbi) || end >= MAX_BLKADDR(sbi)) {
-		ret = -EINVAL;
-		goto out;
-	}
 do_more:
 	if (!range.sync) {
 		if (!mutex_trylock(&sbi->gc_mutex)) {