xhci: trace debug statements for urb cancellation

This patch defines a new trace event, which is called xhci_dbg_cancel_urb
and belongs to the event class xhci_log_msg, and adds tracepoints that
trace the debug messages related to the removal of a cancelled URB from
the endpoint's transfer ring.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
diff --git a/drivers/usb/host/xhci-trace.h b/drivers/usb/host/xhci-trace.h
index d6c2229..c0eaccc 100644
--- a/drivers/usb/host/xhci-trace.h
+++ b/drivers/usb/host/xhci-trace.h
@@ -52,6 +52,11 @@
 	TP_ARGS(vaf)
 );
 
+DEFINE_EVENT(xhci_log_msg, xhci_dbg_cancel_urb,
+	TP_PROTO(struct va_format *vaf),
+	TP_ARGS(vaf)
+);
+
 DECLARE_EVENT_CLASS(xhci_log_ctx,
 	TP_PROTO(struct xhci_hcd *xhci, struct xhci_container_ctx *ctx,
 		 unsigned int ep_num),