idmap2: fix clang-tidy warnings [readability-*]

Bug: 120024673
Test: mmm frameworks/base/cmds/idmap2; check output
Change-Id: I1565afac8d34e4347d8c946228d1134211e8b435
diff --git a/cmds/idmap2/idmap2d/Main.cpp b/cmds/idmap2/idmap2d/Main.cpp
index d64a87b..4393dcc 100644
--- a/cmds/idmap2/idmap2d/Main.cpp
+++ b/cmds/idmap2/idmap2d/Main.cpp
@@ -37,7 +37,7 @@
 using android::os::Idmap2Service;
 
 int main(int argc ATTRIBUTE_UNUSED, char** argv ATTRIBUTE_UNUSED) {
-  IPCThreadState::self()->disableBackgroundScheduling(true);
+  IPCThreadState::disableBackgroundScheduling(true);
   status_t ret = BinderService<Idmap2Service>::publish();
   if (ret != android::OK) {
     return EXIT_FAILURE;