perf ui hist browser: Fix segfault on 'a' for annotate

There a typo in util/ui/browsers/hists.c that leads to a segfault when you
press the 'a' key on a non-resolved symbol (plain hex address).

LKML-Reference: <20100923201901.GE31726@gambetta>
Signed-off-by: Frederik Deweerdt <frederik.deweerdt@xprog.eu>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/ui/browsers/hists.c b/tools/perf/util/ui/browsers/hists.c
index dafdf67..6866aa4 100644
--- a/tools/perf/util/ui/browsers/hists.c
+++ b/tools/perf/util/ui/browsers/hists.c
@@ -773,7 +773,7 @@
 
 			switch (key) {
 			case 'a':
-				if (browser->selection->map == NULL &&
+				if (browser->selection->map == NULL ||
 				    browser->selection->map->dso->annotate_warned)
 					continue;
 				goto do_annotate;