cpplint: Cleanup errors

Cleanup errors from upstream cpplint in preparation
for moving art's cpplint fork to upstream tip-of-tree cpplint.

Test: cd art && mm
Bug: 68951293
Change-Id: I15faed4594cbcb8399850f8bdee39d42c0c5b956
diff --git a/compiler/utils/assembler_test.h b/compiler/utils/assembler_test.h
index ad84412..0cb8bbb 100644
--- a/compiler/utils/assembler_test.h
+++ b/compiler/utils/assembler_test.h
@@ -734,7 +734,7 @@
   }
 
  protected:
-  explicit AssemblerTest() {}
+  AssemblerTest() {}
 
   void SetUp() OVERRIDE {
     allocator_.reset(new ArenaAllocator(&pool_));