rtl8723au: Use correct pipe type for USB interrupts

Use a correct pipe type when filling un interrupt urbs. This should
finally take care of the WARN() messages on the console when USB urbs
are submitted.

Signed-off-by: Jes Sorensen <Jes.Sorensen@redhat.com>
Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>