Remove unnecessary `explicit` qualifiers on constructors.

Change-Id: Id12e392ad50f66a6e2251a68662b7959315dc567
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index b44c5ba..d93ef1b 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -360,8 +360,7 @@
 
 class SuspendCheckSlowPathARM64 : public SlowPathCodeARM64 {
  public:
-  explicit SuspendCheckSlowPathARM64(HSuspendCheck* instruction,
-                                     HBasicBlock* successor)
+  SuspendCheckSlowPathARM64(HSuspendCheck* instruction, HBasicBlock* successor)
       : instruction_(instruction), successor_(successor) {}
 
   void EmitNativeCode(CodeGenerator* codegen) OVERRIDE {