perf tools: Convert critical messages to ui__error()

There were places where use ui__warning (or even fprintf) to show
critical messages. This patch converts them to ui__error so that the
front-end code can implement appropriate behavior.

Signed-off-by: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/1338265382-6872-3-git-send-email-namhyung@gmail.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/builtin-report.c b/tools/perf/builtin-report.c
index d58e414..8c767c6 100644
--- a/tools/perf/builtin-report.c
+++ b/tools/perf/builtin-report.c
@@ -251,13 +251,13 @@
 
 	if (!(self->sample_type & PERF_SAMPLE_CALLCHAIN)) {
 		if (sort__has_parent) {
-			ui__warning("Selected --sort parent, but no "
+			ui__error("Selected --sort parent, but no "
 				    "callchain data. Did you call "
 				    "'perf record' without -g?\n");
 			return -EINVAL;
 		}
 		if (symbol_conf.use_callchain) {
-			ui__warning("Selected -g but no callchain data. Did "
+			ui__error("Selected -g but no callchain data. Did "
 				    "you call 'perf record' without -g?\n");
 			return -1;
 		}
@@ -266,17 +266,15 @@
 		   !symbol_conf.use_callchain) {
 			symbol_conf.use_callchain = true;
 			if (callchain_register_param(&callchain_param) < 0) {
-				ui__warning("Can't register callchain "
-					    "params.\n");
+				ui__error("Can't register callchain params.\n");
 				return -EINVAL;
 			}
 	}
 
 	if (sort__branch_mode == 1) {
 		if (!(self->sample_type & PERF_SAMPLE_BRANCH_STACK)) {
-			fprintf(stderr, "selected -b but no branch data."
-					" Did you call perf record without"
-					" -b?\n");
+			ui__error("Selected -b but no branch data. "
+				  "Did you call perf record without -b?\n");
 			return -1;
 		}
 	}
@@ -420,7 +418,7 @@
 	}
 
 	if (nr_samples == 0) {
-		ui__warning("The %s file has no samples!\n", session->filename);
+		ui__error("The %s file has no samples!\n", session->filename);
 		goto out_delete;
 	}