ext4: convert ext4_bread() to use the ERR_PTR convention

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 0b28b36..896e452 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5305,7 +5305,6 @@
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
-	int err = 0;
 	int offset = off & (sb->s_blocksize - 1);
 	int tocopy;
 	size_t toread;
@@ -5320,9 +5319,9 @@
 	while (toread > 0) {
 		tocopy = sb->s_blocksize - offset < toread ?
 				sb->s_blocksize - offset : toread;
-		bh = ext4_bread(NULL, inode, blk, 0, &err);
-		if (err)
-			return err;
+		bh = ext4_bread(NULL, inode, blk, 0);
+		if (IS_ERR(bh))
+			return PTR_ERR(bh);
 		if (!bh)	/* A hole? */
 			memset(data, 0, tocopy);
 		else
@@ -5343,8 +5342,7 @@
 {
 	struct inode *inode = sb_dqopt(sb)->files[type];
 	ext4_lblk_t blk = off >> EXT4_BLOCK_SIZE_BITS(sb);
-	int err = 0;
-	int offset = off & (sb->s_blocksize - 1);
+	int err, offset = off & (sb->s_blocksize - 1);
 	struct buffer_head *bh;
 	handle_t *handle = journal_current_handle();
 
@@ -5365,14 +5363,16 @@
 		return -EIO;
 	}
 
-	bh = ext4_bread(handle, inode, blk, 1, &err);
+	bh = ext4_bread(handle, inode, blk, 1);
+	if (IS_ERR(bh))
+		return PTR_ERR(bh);
 	if (!bh)
 		goto out;
 	BUFFER_TRACE(bh, "get write access");
 	err = ext4_journal_get_write_access(handle, bh);
 	if (err) {
 		brelse(bh);
-		goto out;
+		return err;
 	}
 	lock_buffer(bh);
 	memcpy(bh->b_data+offset, data, len);
@@ -5381,8 +5381,6 @@
 	err = ext4_handle_dirty_metadata(handle, NULL, bh);
 	brelse(bh);
 out:
-	if (err)
-		return err;
 	if (inode->i_size < off + len) {
 		i_size_write(inode, off + len);
 		EXT4_I(inode)->i_disksize = inode->i_size;