cpplint: Remove many unnecessary NOLINT

Now that we updated to upstream cpplint, a lot of these NOLINTs are no
longer necessary.

Bug: 68951293
Change-Id: If8ed5ffe89727f313f907a214b6d8fd2a2eddbad
diff --git a/imgdiag/imgdiag.cc b/imgdiag/imgdiag.cc
index f0c9158..05fce96 100644
--- a/imgdiag/imgdiag.cc
+++ b/imgdiag/imgdiag.cc
@@ -1610,7 +1610,7 @@
   // BacktraceMap used for finding the memory mapping of the image file.
   std::unique_ptr<BacktraceMap> proc_maps_;
   // Boot image mapping.
-  backtrace_map_t boot_map_{};  // NOLINT
+  backtrace_map_t boot_map_{};
   // The size of the boot image mapping.
   size_t boot_map_size_;
   // The contents of /proc/<image_diff_pid_>/maps.