Clean up option handling in papi_decode
Clean up option handling in papi_decode

papi_decode used strstr() to match options; this can lead to inexact
matchs. The code should used strcmp instead.  Make sure command name
is not processed as an option.  Also print help iformation is some
argument is not understood.

Signed-off-by: William Cohen <7ad90ad7035ff1d5b2ddada0aaffa89765886b13@redhat.com>

arm-hpc/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi,pyrovski/papi,pyrovski/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,pyrovski/papi,arm-hpc/papi,pyrovski/papi,pyrovski/papi,arm-hpc/papi,arm-hpc/papi