events: convert to idr_alloc()

Convert to the much saner new idr interface.
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

kernel/events/core.c

@@ -5965,13 +5965,9 @@ int perf_pmu_register(struct pmu *pmu, char *name, int type)
 	pmu->name = name;
 
 	if (type < 0) {
-		int err = idr_pre_get(&pmu_idr, GFP_KERNEL);
-		if (!err)
-			goto free_pdc;
-
-		err = idr_get_new_above(&pmu_idr, pmu, PERF_TYPE_MAX, &type);
-		if (err) {
-			ret = err;
+		type = idr_alloc(&pmu_idr, pmu, PERF_TYPE_MAX, 0, GFP_KERNEL);
+		if (type < 0) {
+			ret = type;
 			goto free_pdc;
 		}
 	}