xfs: don't call xfs_bmap_same_rtgroup in xfs_bmap_add_extent_hole_delay

xfs_bmap_add_extent_hole_delay works entirely on delalloc extents, for
which xfs_bmap_same_rtgroup doesn't make sense.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>