runtime: move getopts to run_tests.sh

We don't need to check options in standalone tests, kick the
loop and usage() function out to run_tests.sh

Signed-off-by: Andrew Jones <drjones@redhat.com>
Message-Id: <1453474709-10679-6-git-send-email-drjones@redhat.com>
Reviewed-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>