ext4: remove an unnecessary if statement in __ext4_get_inode_loc()

The "if (!buffer_uptodate(bh))" hunk covered almost the whole code after
getting buffer in __ext4_get_inode_loc() which seems unnecessary, remove
it and switch to check ext4_buffer_uptodate(), it simplify code and make
it more readable.
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20210826130412.3921207-3-yi.zhang@huawei.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/inode.c

@@ -4337,15 +4337,10 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
 	bh = sb_getblk(sb, block);
 	if (unlikely(!bh))
 		return -ENOMEM;
-	if (!buffer_uptodate(bh)) {
-		lock_buffer(bh);
-
-		if (ext4_buffer_uptodate(bh)) {
-			/* someone brought it uptodate while we waited */
-			unlock_buffer(bh);
+	if (ext4_buffer_uptodate(bh))
 		goto has_buffer;
-		}
 
+	lock_buffer(bh);
 	/*
 	 * If we have all information of the inode in memory and this
 	 * is the only valid inode in the block, we need not read the
@@ -4430,7 +4425,6 @@ static int __ext4_get_inode_loc(struct super_block *sb, unsigned long ino,
 		brelse(bh);
 		return -EIO;
 	}
-	}
 has_buffer:
 	iloc->bh = bh;
 	return 0;