perf tools: Remove cast of non-variadic function to variadic

The 4fb7107 (perf ui/hist: Consolidate hpp helpers) cset introduced
a cast of percent_color_snprintf to a function pointer type with
varargs.  Change percent_color_snprintf to be variadic and remove the
cast.

The symptom of this was all percentages being reported as 0.00% in perf
report --stdio output on the armhf arch.

Signed-off-by: Michael Hudson-Doyle <michael.hudson@linaro.org>
Acked-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: Jean Pihet <jean.pihet@linaro.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Link: http://lkml.kernel.org/r/87zjppvw7y.fsf@canonical.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/ui/hist.c

@@ -117,7 +117,7 @@ static int hpp__color_##_type(struct perf_hpp_fmt *fmt __maybe_unused,		\
 			      struct perf_hpp *hpp, struct hist_entry *he) 	\
 {										\
 	return __hpp__fmt(hpp, he, he_get_##_field, " %6.2f%%",			\
-			  (hpp_snprint_fn)percent_color_snprintf, true);	\
+			  percent_color_snprintf, true);			\
 }
 
 #define __HPP_ENTRY_PERCENT_FN(_type, _field)					\

tools/perf/util/color.c

@@ -318,8 +318,15 @@ int percent_color_fprintf(FILE *fp, const char *fmt, double percent)
 	return r;
 }
 
-int percent_color_snprintf(char *bf, size_t size, const char *fmt, double percent)
+int percent_color_snprintf(char *bf, size_t size, const char *fmt, ...)
 {
-	const char *color = get_percent_color(percent);
+	va_list args;
+	double percent;
+	const char *color;
+
+	va_start(args, fmt);
+	percent = va_arg(args, double);
+	va_end(args);
+	color = get_percent_color(percent);
 	return color_snprintf(bf, size, color, fmt, percent);
 }

tools/perf/util/color.h

@@ -39,7 +39,7 @@ int color_fprintf(FILE *fp, const char *color, const char *fmt, ...);
 int color_snprintf(char *bf, size_t size, const char *color, const char *fmt, ...);
 int color_fprintf_ln(FILE *fp, const char *color, const char *fmt, ...);
 int color_fwrite_lines(FILE *fp, const char *color, size_t count, const char *buf);
-int percent_color_snprintf(char *bf, size_t size, const char *fmt, double percent);
+int percent_color_snprintf(char *bf, size_t size, const char *fmt, ...);
 int percent_color_fprintf(FILE *fp, const char *fmt, double percent);
 const char *get_percent_color(double percent);