xfs/3{43,32}: adapt tests for rt extent size greater than 1

xfs/3{43,32}: adapt tests for rt extent size greater than 1

Both of these tests for the realtime volume can fail when the rt extent
size is larger than a single block.

332 is a read-write functionality test that encodes md5sum in the
output, so we need to skip it if $blksz isn't congruent with the extent
size, because the fcollapse call will fail.

343 is a test of the rmap btree, so the fix here is simpler -- make
$blksz the file allocation unit, and get rid of the md5sum in the
golden output.

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