ext4: correct error value of function verifying dx checksum

ext4_dx_csum_verify() returns the success return value in two checksum
verification failure cases. We need to set the return values to zero
as failure like ext4_dirent_csum_verify() returning zero when failing
to find a checksum dirent at the tail.
Signed-off-by: Daeho Jeong <daeho.jeong@samsung.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/ext4/namei.c

@@ -445,14 +445,14 @@ static int ext4_dx_csum_verify(struct inode *inode,
 	c = get_dx_countlimit(inode, dirent, &count_offset);
 	if (!c) {
 		EXT4_ERROR_INODE(inode, "dir seems corrupt?  Run e2fsck -D.");
-		return 1;
+		return 0;
 	}
 	limit = le16_to_cpu(c->limit);
 	count = le16_to_cpu(c->count);
 	if (count_offset + (limit * sizeof(struct dx_entry)) >
 	    EXT4_BLOCK_SIZE(inode->i_sb) - sizeof(struct dx_tail)) {
 		warn_no_space_for_csum(inode);
-		return 1;
+		return 0;
 	}
 	t = (struct dx_tail *)(((struct dx_entry *)c) + limit);