perf tools: Be consistent on the type of map->symbols[] interator

In a few cases we were using 'enum map_type' and that triggered this
warning when using clang:

  util/session.c:1923:16: error: comparison of constant 2 with expression of type 'enum map_type' is always true
      [-Werror,-Wtautological-constant-out-of-range-compare]
        for (i = 0; i < MAP__NR_TYPES; ++i) {

Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lkml.kernel.org/n/tip-i6uyo6bsopa2dghnx8qo7rri@git.kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
diff --git a/tools/perf/util/machine.c b/tools/perf/util/machine.c
index a1043cf..71c9720 100644
--- a/tools/perf/util/machine.c
+++ b/tools/perf/util/machine.c
@@ -782,7 +782,7 @@
 
 int __machine__create_kernel_maps(struct machine *machine, struct dso *kernel)
 {
-	enum map_type type;
+	int type;
 	u64 start = machine__get_running_kernel_start(machine, NULL);
 
 	/* In case of renewal the kernel map, destroy previous one */
@@ -813,7 +813,7 @@
 
 void machine__destroy_kernel_maps(struct machine *machine)
 {
-	enum map_type type;
+	int type;
 
 	for (type = 0; type < MAP__NR_TYPES; ++type) {
 		struct kmap *kmap;