After destroying iscsi, nullify iscsi_url's reference to it to prevent a use after free. Detected by clang's AddressSanitizer.
Fixes ARM problems too. Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Dont call READCAPACITY from every single test. Remove two arguments from the test signatures and turn them into globals. remove the ret++ silliness. Tests return 0 : all ok, -2, skipped or -1 : test failed