check: generate section reports between tests

check: generate section reports between tests

Generate the section report between tests so that the summary report
always reflects the outcome of the most recent test.  Two usecases are
envisioned here -- if a cluster-based test runner anticipates that the
testrun could crash the VM, they can set REPORT_DIR to (say) an NFS
mount to preserve the intermediate results.  If the VM does indeed
crash, the scheduler can examine the state of the crashed VM and move
the tests to another VM.  The second usecase is a reporting agent that
runs in the VM to upload live results to a test dashboard.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Leah Rumancik <leah.rumancik@gmail.com>
Tested-by: Leah Rumancik <leah.rumancik@gmail.com>
Signed-off-by: Zorro Lang <zlang@kernel.org>