gralloctest: update test for ARCVM

gralloctest: update test for ARCVM

On ARCVM, the stride obtained from GRALLOC_DRM_GET_STRIDE is the host
stride, and may be larger than the guest stride.

This change also moves the line which prints the next test to execute to
before the test actually runs, so it appears before test failures.

BUG=b:155238003
TEST=tast run DUT arc.Gralloc*

Change-Id: I4594f352fba585fa4bdbaff609f198888b99c8f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/minigbm/+/2500971
Reviewed-by: Gurchetan Singh <gurchetansingh@chromium.org>
Commit-Queue: David Stevens <stevensd@chromium.org>
Tested-by: David Stevens <stevensd@chromium.org>