Fix cpplint's whitespace warnings.

Change-Id: I16b69d773e59b49e8e30227b5aa5cb1959a8930f
diff --git a/src/thread.cc b/src/thread.cc
index e72046c..73b8a94 100644
--- a/src/thread.cc
+++ b/src/thread.cc
@@ -1383,7 +1383,7 @@
             spill_shifts--;  // wind back one as we want the last match
             ref = reinterpret_cast<Object*>(context_->GetGPR(spill_shifts));
           } else {
-            ref = reinterpret_cast<Object*>(frame.GetVReg(m ,reg));
+            ref = reinterpret_cast<Object*>(frame.GetVReg(m, reg));
           }
           if (ref != NULL) {
             root_visitor_(ref, arg_);