unittests: fail if one test fail

vstart_wrapped_tests must return on error if one of the tests
fail.

Signed-off-by: Loic Dachary <loic@dachary.org>
mon: pool create will not fail if the type differs

It looked like it worked because the wrapper hide the error. The failing
tests are commented out so that the other tests can be used.

Signed-off-by: Loic Dachary <loic@dachary.org>
Merge pull request #979 from dachary/wip-wrapped-vstart-errors

vstart_wrapped_tests must fail if one test fail 

Reviewed-by: Sage Weil <sage@inktank.com>