xfs: simplify di_flags2 inheritance in xfs_ialloc

di_flags2 is initialized to zero for v4 and earlier file systems.  This
means di_flags2 can only be non-zero for a v5 file systems, in which
case both the parent and child inodes can store the field.  Remove the
extra di_version check, and also remove the rather pointless local
di_flags2 variable while at it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

fs/xfs/xfs_inode.c

@@ -907,20 +907,13 @@ xfs_ialloc(
 
 			ip->i_d.di_flags |= di_flags;
 		}
-		if (pip &&
-		    (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY) &&
-		    pip->i_d.di_version == 3 &&
-		    ip->i_d.di_version == 3) {
-			uint64_t	di_flags2 = 0;
-
+		if (pip && (pip->i_d.di_flags2 & XFS_DIFLAG2_ANY)) {
 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) {
-				di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
+				ip->i_d.di_flags2 |= XFS_DIFLAG2_COWEXTSIZE;
 				ip->i_d.di_cowextsize = pip->i_d.di_cowextsize;
 			}
 			if (pip->i_d.di_flags2 & XFS_DIFLAG2_DAX)
-				di_flags2 |= XFS_DIFLAG2_DAX;
-
-			ip->i_d.di_flags2 |= di_flags2;
+				ip->i_d.di_flags2 |= XFS_DIFLAG2_DAX;
 		}
 		/* FALLTHROUGH */
 	case S_IFLNK: