xfs: use realtime EFI to free extents when realtime rmap is enabled

xfs: use realtime EFI to free extents when realtime rmap is enabled

When rmap is enabled, XFS expects a certain order of operations, which
is: 1) remove the file mapping, 2) remove the reverse mapping, and then
3) free the blocks.  xfs_bmap_del_extent_real tries to do 1 and 3 in the
same transaction, which means that when rtrmap is enabled, we have to
use realtime EFIs to maintain the expected order.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>