hp-wmi: check query return value in hp_wmi_perform_query

Check BIOS provided return value code in hp_wmi_perform_query and print
a warning on error. Printing is suppressed for HPWMI_RET_UNKNOWN_CMDTYPE
which is returned when the command type is unsupported.

Signed-off-by: Anssi Hannula <anssi.hannula@iki.fi>
Signed-off-by: Matthew Garrett <mjg@redhat.com>