tests: Run the iotests during "make check" again

tests: Run the iotests during "make check" again

People often forget to run the iotests before submitting patches or pull
requests - this is likely due to the fact that we do not run the tests
during our mandatory "make check" tests yet. Now that we've got a proper
"auto" group of iotests that should be fine to run in every environment,
we can enable the iotests during "make check" again by running the "auto"
tests by default from the check-block.sh script.

Some cases still need to be checked first, though: iotests need bash and
GNU sed (otherwise they fail), and if gprof is enabled, it spoils the
output of some test cases causing them to fail. So if we detect that one
of the required programs is missing or that gprof is enabled, we still
have to skip the iotests to avoid failures.

And finally, since we are using check-block.sh now again, this patch also
removes the qemu-iotests-quick.sh script since we do not need that anymore
(and having two shell wrapper scripts around the block tests seems rather
confusing than helpful).

Message-Id: <20190717111947.30356-4-thuth@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
[AJB: -makecheck to check-block.sh, move check-block to start and gate it]
Signed-off-by: Alex Bennée <alex.bennee@linaro.org>