perf tools: Generalize percent_color_snprintf()

Make percent_color_snprintf() handle negative values correctly.
Signed-off-by: Ramkumar Ramachandra <artagnon@gmail.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Link: http://lkml.kernel.org/r/1388388861-7931-2-git-send-email-artagnon@gmail.comSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/color.c

 #include <linux/kernel.h>
 #include "cache.h"
 #include "color.h"
+#include <math.h>
 
 int perf_use_color_default = -1;
 
@@ -298,10 +299,10 @@ const char *get_percent_color(double percent)
 	 * entries in green - and keep the low overhead places
 	 * normal:
 	 */
-	if (percent >= MIN_RED)
+	if (fabs(percent) >= MIN_RED)
 		color = PERF_COLOR_RED;
 	else {
-		if (percent > MIN_GREEN)
+		if (fabs(percent) > MIN_GREEN)
 			color = PERF_COLOR_GREEN;
 	}
 	return color;