xfs: simplify a check in xfs_ioctl_setattr_check_cowextsize

xfs: simplify a check in xfs_ioctl_setattr_check_cowextsize

commit e8f49ad06cd59e40a470fbd2a00f1918a34ed126 upstream.

Only v5 file systems can have the reflink feature, and those will
always use the large dinode format.  Remove the extra check for the
inode version.

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>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Acked-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>