mac80211: rename driver-trace file

This file will contain more soon, so
rename it to just trace.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>

net/mac80211/trace.c

@@ -0,0 +1,9 @@
+/* bug in tracepoint.h, it should include this */
+#include <linux/module.h>
+
+/* sparse isn't too happy with all macros... */
+#ifndef __CHECKER__
+#include "driver-ops.h"
+#define CREATE_TRACE_POINTS
+#include "trace.h"
+#endif