perf tools: Fix const char type propagation

The following perf build warnings/errors in function
argument types:

  builtin-sched.c:1894: warning: passing argument 1 of 'sort_dimension__add' discards qualifiers from pointer target type
  util/trace-event-parse.c:685: warning: passing argument 2 of 'read_expected' discards qualifiers from pointer target type
  util/trace-event-parse.c:741: warning: passing argument 4 of 'test_type_token' discards qualifiers from pointer target type
  util/trace-event-parse.c:706: warning: passing argument 2 of 'read_expected_item' discards qualifiers from pointer target type

... trigger because older GCC is not able to prove that
sort_dimension__add() does not change the string.

Some goes for test_type_token().

Fix this by improving type consistency.

Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091005131729.78444bfb.randy.dunlap@oracle.com>
[ Also remove ugly type cast now unnecessary. ]
Signed-off-by: Ingo Molnar <mingo@elte.hu>

tools/perf/builtin-sched.c

@@ -1287,7 +1287,7 @@ static struct sort_dimension *available_sorts[] = {
 
 static LIST_HEAD(sort_list);
 
-static int sort_dimension__add(char *tok, struct list_head *list)
+static int sort_dimension__add(const char *tok, struct list_head *list)
 {
 	int i;
 
@@ -1917,7 +1917,7 @@ static void setup_sorting(void)
 
 	free(str);
 
-	sort_dimension__add((char *)"pid", &cmp_pid);
+	sort_dimension__add("pid", &cmp_pid);
 }
 
 static const char *record_args[] = {

tools/perf/util/trace-event-parse.c

@@ -618,7 +618,7 @@ static int test_type(enum event_type type, enum event_type expect)
 }
 
 static int test_type_token(enum event_type type, char *token,
-		    enum event_type expect, char *expect_tok)
+		    enum event_type expect, const char *expect_tok)
 {
 	if (type != expect) {
 		die("Error: expected type %d but read %d",
@@ -650,7 +650,7 @@ static int read_expect_type(enum event_type expect, char **tok)
 	return __read_expect_type(expect, tok, 1);
 }
 
-static int __read_expected(enum event_type expect, char *str, int newline_ok)
+static int __read_expected(enum event_type expect, const char *str, int newline_ok)
 {
 	enum event_type type;
 	char *token;
@@ -668,12 +668,12 @@ static int __read_expected(enum event_type expect, char *str, int newline_ok)
 	return 0;
 }
 
-static int read_expected(enum event_type expect, char *str)
+static int read_expected(enum event_type expect, const char *str)
 {
 	return __read_expected(expect, str, 1);
 }
 
-static int read_expected_item(enum event_type expect, char *str)
+static int read_expected_item(enum event_type expect, const char *str)
 {
 	return __read_expected(expect, str, 0);
 }