After introducing the scsi/ subdirectory, there will be a scsi_build_sense
function that is the same as scsi_req_build_sense but without needing
a SCSIRequest.  The existing scsi_build_sense function gets in the way,
remove it.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>