perf top: Honour --hide_{user,kernel}_symbols and the 'U' hotkey

The new decay routine (__hists__decay_entries) wasn't being passed the
toggles, fix it.

Reported-by: Mike Galbraith <efault@gmx.de>
Cc: David Ahern <dsahern@gmail.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lkml.kernel.org/n/tip-hg6m0mi1colket982oq9hhly@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/hist.c b/tools/perf/util/hist.c
index a7193c5..48da373 100644
--- a/tools/perf/util/hist.c
+++ b/tools/perf/util/hist.c
@@ -108,7 +108,8 @@
 	return he->period == 0;
 }
 
-static void __hists__decay_entries(struct hists *hists, bool threaded)
+static void __hists__decay_entries(struct hists *hists, bool zap_user,
+				   bool zap_kernel, bool threaded)
 {
 	struct rb_node *next = rb_first(&hists->entries);
 	struct hist_entry *n;
@@ -121,7 +122,10 @@
 		 * case some it gets new samples, we'll eventually free it when
 		 * the user stops browsing and it agains gets fully decayed.
 		 */
-		if (hists__decay_entry(hists, n) && !n->used) {
+		if (((zap_user && n->level == '.') ||
+		     (zap_kernel && n->level != '.') ||
+		     hists__decay_entry(hists, n)) &&
+		    !n->used) {
 			rb_erase(&n->rb_node, &hists->entries);
 
 			if (sort__need_collapse || threaded)
@@ -133,14 +137,15 @@
 	}
 }
 
-void hists__decay_entries(struct hists *hists)
+void hists__decay_entries(struct hists *hists, bool zap_user, bool zap_kernel)
 {
-	return __hists__decay_entries(hists, false);
+	return __hists__decay_entries(hists, zap_user, zap_kernel, false);
 }
 
-void hists__decay_entries_threaded(struct hists *hists)
+void hists__decay_entries_threaded(struct hists *hists,
+				   bool zap_user, bool zap_kernel)
 {
-	return __hists__decay_entries(hists, true);
+	return __hists__decay_entries(hists, zap_user, zap_kernel, true);
 }
 
 /*