perf units: Move parse_tag_value() to units.[ch]

Its basically to do units handling, so move to a more appropriately
named object.

Cc: Adrian Hunter <[e-mail]>
Cc: David Ahern <[e-mail]>
Cc: Jiri Olsa <[e-mail]>
Cc: Namhyung Kim <[e-mail]>
Cc: Wang Nan <[e-mail]>
Link: http://lkml.kernel.org/n/[e-mail]
Signed-off-by: Arnaldo Carvalho de Melo <[e-mail]>

tools/perf/util/units.c

···
 #include "units.h"
 #include <inttypes.h>
+#include <limits.h>
+#include <stdlib.h>
+#include <string.h>
 #include <linux/kernel.h>
 #include <linux/time64.h>
+
+unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
+{
+	struct parse_tag *i = tags;
+
+	while (i->tag) {
+		char *s = strchr(str, i->tag);
+
+		if (s) {
+			unsigned long int value;
+			char *endptr;
+
+			value = strtoul(str, &endptr, 10);
+			if (s != endptr)
+				break;
+
+			if (value > ULONG_MAX / i->mult)
+				break;
+			value *= i->mult;
+			return value;
+		}
+		i++;
+	}
+
+	return (unsigned long) -1;
+}
 
 unsigned long convert_unit(unsigned long value, char *unit)
 {

tools/perf/util/units.h

···
 #include <stddef.h>
 #include <linux/types.h>
 
+struct parse_tag {
+	char tag;
+	int  mult;
+};
+
+unsigned long parse_tag_value(const char *str, struct parse_tag *tags);
+
 unsigned long convert_unit(unsigned long value, char *unit);
 int unit_number__scnprintf(char *buf, size_t size, u64 n);
 

tools/perf/util/util.c

···
 	return p - ptr;
 }
 
-unsigned long parse_tag_value(const char *str, struct parse_tag *tags)
-{
-	struct parse_tag *i = tags;
-
-	while (i->tag) {
-		char *s;
-
-		s = strchr(str, i->tag);
-		if (s) {
-			unsigned long int value;
-			char *endptr;
-
-			value = strtoul(str, &endptr, 10);
-			if (s != endptr)
-				break;
-
-			if (value > ULONG_MAX / i->mult)
-				break;
-			value *= i->mult;
-			return value;
-		}
-		i++;
-	}
-
-	return (unsigned long) -1;
-}
-
 int perf_event_paranoid(void)
 {
 	int value;

tools/perf/util/util.h

···
 extern unsigned int page_size;
 extern int cacheline_size;
 
-struct parse_tag {
-	char tag;
-	int mult;
-};
-
-unsigned long parse_tag_value(const char *str, struct parse_tag *tags);
-
 bool find_process(const char *name);
 
 int fetch_kernel_version(unsigned int *puint,