drm_hwcomposer: Enable readability-math-missing-parentheses tidy check

... and fix all related warnings.

Change-Id: Ic122235524e567f2be5040ae7742fefb531a9766
Signed-off-by: Roman Stratiienko <r.stratiienko@gmail.com>
diff --git a/drm/ResourceManager.cpp b/drm/ResourceManager.cpp
index 9c68816..c866263 100644
--- a/drm/ResourceManager.cpp
+++ b/drm/ResourceManager.cpp
@@ -124,7 +124,7 @@
   struct timespec ts {};
   clock_gettime(CLOCK_MONOTONIC, &ts);
   constexpr int64_t kNsInSec = 1000000000LL;
-  return int64_t(ts.tv_sec) * kNsInSec + int64_t(ts.tv_nsec);
+  return (int64_t(ts.tv_sec) * kNsInSec) + int64_t(ts.tv_nsec);
 }
 
 void ResourceManager::UpdateFrontendDisplays() {
diff --git a/drm/VSyncWorker.cpp b/drm/VSyncWorker.cpp
index 64152ab..defbe42 100644
--- a/drm/VSyncWorker.cpp
+++ b/drm/VSyncWorker.cpp
@@ -124,7 +124,7 @@
   if (last_timestamp_ < 0)
     return current + frame_ns;
 
-  return frame_ns * ((current - last_timestamp_) / frame_ns + 1) +
+  return (frame_ns * ((current - last_timestamp_) / frame_ns + 1)) +
          last_timestamp_;
 }