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

Bug: 120024673
Test: mmm frameworks/base/cmds/idmap2; check output
Change-Id: I1565afac8d34e4347d8c946228d1134211e8b435
diff --git a/cmds/idmap2/libidmap2/Idmap.cpp b/cmds/idmap2/libidmap2/Idmap.cpp
index 1ef3267..0ddc224 100644
--- a/cmds/idmap2/libidmap2/Idmap.cpp
+++ b/cmds/idmap2/libidmap2/Idmap.cpp
@@ -196,8 +196,9 @@
 std::unique_ptr<const IdmapData::TypeEntry> IdmapData::TypeEntry::FromBinaryStream(
     std::istream& stream) {
   std::unique_ptr<IdmapData::TypeEntry> data(new IdmapData::TypeEntry());
-
-  uint16_t target_type16, overlay_type16, entry_count;
+  uint16_t target_type16;
+  uint16_t overlay_type16;
+  uint16_t entry_count;
   if (!Read16(stream, &target_type16) || !Read16(stream, &overlay_type16) ||
       !Read16(stream, &entry_count) || !Read16(stream, &data->entry_offset_)) {
     return nullptr;
@@ -282,25 +283,25 @@
   }
 
   const LoadedArsc* target_arsc = target_apk_assets.GetLoadedArsc();
-  if (!target_arsc) {
+  if (target_arsc == nullptr) {
     out_error << "error: failed to load target resources.arsc" << std::endl;
     return nullptr;
   }
 
   const LoadedArsc* overlay_arsc = overlay_apk_assets.GetLoadedArsc();
-  if (!overlay_arsc) {
+  if (overlay_arsc == nullptr) {
     out_error << "error: failed to load overlay resources.arsc" << std::endl;
     return nullptr;
   }
 
   const LoadedPackage* target_pkg = GetPackageAtIndex0(*target_arsc);
-  if (!target_pkg) {
+  if (target_pkg == nullptr) {
     out_error << "error: failed to load target package from resources.arsc" << std::endl;
     return nullptr;
   }
 
   const LoadedPackage* overlay_pkg = GetPackageAtIndex0(*overlay_arsc);
-  if (!overlay_pkg) {
+  if (overlay_pkg == nullptr) {
     out_error << "error: failed to load overlay package from resources.arsc" << std::endl;
     return nullptr;
   }