xhci: Be less verbose during URB cancellation.

xhci: Be less verbose during URB cancellation.

With devices that can need up to 128 segments (with 64 TRBs per
segment), we can't afford to print out the entire endpoint ring every
time an URB is canceled.  Instead, print the offset of the TRB, along
with device pathname and endpoint number.

Only print DMA addresses, since virtual addresses of internal structures
are not useful.  Change the cancellation code to be more clear about
what steps of the cancellation it is in the process of doing (queueing
the request, handling the stop endpoint command, turning the TDs into
no-ops, or moving the dequeue pointers).

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