perf/x86/intel: Fix the name of perf METRICS

Bit 15 of the PERF_CAPABILITIES MSR indicates that the perf METRICS
feature is supported. The perf METRICS is not a PEBS feature.

Rename pebs_metrics_available perf_metrics.

The bit is not used in the current code. It will be used in a later
patch.
Signed-off-by: NKan Liang <kan.liang@linux.intel.com>
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200723171117.9918-6-kan.liang@linux.intel.com

arch/x86/events/perf_event.h

@@ -537,7 +537,7 @@ union perf_capabilities {
 		 */
 		u64	full_width_write:1;
 		u64     pebs_baseline:1;
-		u64	pebs_metrics_available:1;
+		u64	perf_metrics:1;
 		u64	pebs_output_pt_available:1;
 	};
 	u64	capabilities;