perf kallsyms: Adopt hex2u64 from tools/perf/util/util.h

Just removing more stuff from tools/perf/, this is mostly used in the
kallsyms parsing and in places in perf where kallsyms is involved, so we
get it for free there.

With this we reduce a bit more util.h.

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

tools/lib/symbol/kallsyms.c

···
 	return symbol_type == 'T' || symbol_type == 'W';
 }
 
+/*
+ * While we find nice hex chars, build a long_val.
+ * Return number of chars processed.
+ */
+int hex2u64(const char *ptr, u64 *long_val)
+{
+	char *p;
+
+	*long_val = strtoull(ptr, &p, 16);
+
+	return p - ptr;
+}
+
 int kallsyms__parse(const char *filename, void *arg,
 		    int (*process_symbol)(void *arg, const char *name,
 					  char type, u64 start))

tools/lib/symbol/kallsyms.h

···
 	return isupper(type) ? STB_GLOBAL : STB_LOCAL;
 }
 
+int hex2u64(const char *ptr, u64 *long_val);
+
 u8 kallsyms2elf_type(char type);
 
 bool kallsyms__is_function(char symbol_type);

tools/perf/util/util.c

···
 	return n;
 }
 
-/*
- * While we find nice hex chars, build a long_val.
- * Return number of chars processed.
- */
-int hex2u64(const char *ptr, u64 *long_val)
-{
-	char *p;
-
-	*long_val = strtoull(ptr, &p, 16);
-
-	return p - ptr;
-}
-
 int perf_event_paranoid(void)
 {
 	int value;

tools/perf/util/util.h

···
 ssize_t writen(int fd, const void *buf, size_t n);
 
 size_t hex_width(u64 v);
-int hex2u64(const char *ptr, u64 *val);
 
 extern unsigned int page_size;
 int __pure cacheline_size(void);