tools perf util: Make rm_rf(path) argument const

rm_rf() doesn't modify its path argument, and a future caller will pass
a string constant into it to delete.

Signed-off-by: Joe Stringer <joe@ovn.org>
Cc: Alexei Starovoitov <ast@fb.com>
Cc: Daniel Borkmann <daniel@iogearbox.net>
Cc: Wang Nan <wangnan0@huawei.com>
Cc: netdev@vger.kernel.org
Link: http://lkml.kernel.org/r/20170126212001.14103-5-joe@ovn.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/util/util.c

@@ -85,7 +85,7 @@ int mkdir_p(char *path, mode_t mode)
 	return (stat(path, &st) && mkdir(path, mode)) ? -1 : 0;
 }
 
-int rm_rf(char *path)
+int rm_rf(const char *path)
 {
 	DIR *dir;
 	int ret = 0;

tools/perf/util/util.h

@@ -209,7 +209,7 @@ static inline int sane_case(int x, int high)
 }
 
 int mkdir_p(char *path, mode_t mode);
-int rm_rf(char *path);
+int rm_rf(const char *path);
 struct strlist *lsdir(const char *name, bool (*filter)(const char *, struct dirent *));
 bool lsdir_no_dot_filter(const char *name, struct dirent *d);
 int copyfile(const char *from, const char *to);