Fix presubmit (r6209).

BUG=
TEST=

Review URL: http://codereview.chromium.org/6029012

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6213 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/lithium-arm.h

@@ -1653,7 +1653,7 @@ class LCheckFunction: public LUnaryOperation {
 
 class LCheckInstanceType: public LUnaryOperation {
  public:
-  LCheckInstanceType(LOperand* use) : LUnaryOperation(use) { }
+  explicit LCheckInstanceType(LOperand* use) : LUnaryOperation(use) { }
 
   DECLARE_CONCRETE_INSTRUCTION(CheckInstanceType, "check-instance-type")
   DECLARE_HYDROGEN_ACCESSOR(CheckInstanceType)