qemu-iotests: move check-block back to Makefiles

check-block has its own test harness, unlike every other test.  If
we capture its output, as is in general nicer to do without V=1,
there will be no sign of progress.  So for lack of a better option
just move the invocation of the test back to Makefile rules.

As a side effect, this will also fix "make check" in --disable-tools
builds, as they were trying to run qemu-iotests without having
made qemu-img before.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tests/qemu-iotests/meson.build

@@ -4,7 +4,3 @@ if 'CONFIG_LINUX' in config_host
 else
     socket_scm_helper = []
 endif
-test('qemu-iotests', sh, args: [files('../check-block.sh')],
-     depends: [qemu_block_tools, emulators, socket_scm_helper],
-     suite: 'block', timeout: 10000)
-