perf tools: Fix "==" into "=" in ui_browser__warning assignment

Convert "==" into "=" in ui_browser__warning assignment.

Bug description: https://bugzilla.kernel.org/show_bug.cgi?id=76751

Reported-by: David Binderman <dcb314@hotmail.com>
Signed-off-by: Dianfang Zhang <zhangdianfang@huawei.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Jean Delvare <jdelvare@suse.de>
Link: http://lkml.kernel.org/r/20140530154709.GC1202@kernel.org
[ changed the changelog a bit ]
Signed-off-by: Jiri Olsa <jolsa@kernel.org>

tools/perf/ui/browser.c

@@ -194,7 +194,7 @@ int ui_browser__warning(struct ui_browser *browser, int timeout,
 		ui_helpline__vpush(format, args);
 		va_end(args);
 	} else {
-		while ((key == ui__question_window("Warning!", text,
+		while ((key = ui__question_window("Warning!", text,
 						   "Press any key...",
 						   timeout)) == K_RESIZE)
 			ui_browser__handle_resize(browser);