Fix cpplint whitespace/comments issues

Change-Id: Iae286862c85fb8fd8901eae1204cd6d271d69496
diff --git a/compiler/sea_ir/instruction_tools.cc b/compiler/sea_ir/instruction_tools.cc
index 5433591..9627497 100644
--- a/compiler/sea_ir/instruction_tools.cc
+++ b/compiler/sea_ir/instruction_tools.cc
@@ -794,4 +794,4 @@
   // FF UNUSED_FF
   DF_NOP
 };
-} // end namespace sea_ir
+}  // namespace sea_ir