ts a Transfer Event with a successful completion
code on the ring for the same TD.  The xHCI driver correctly processes the
short transfer completion code, gives the URB back to the driver, and then
prints a warning in dmesg about the spurious event.  These warning
messages really fill up dmesg when an HD webcam is plugged into xHCI.

This spurious successful event behavior isn't technically disallowed by
the xHCI specification, so make the xHCI driver just ignore the spurious
completion event.

Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Kæw