Clean up comments to be consistent with code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37798 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/Makefile.rules b/Makefile.rules
index 3da1135..d35447d 100644
--- a/Makefile.rules
+++ b/Makefile.rules
@@ -260,8 +260,9 @@
   C.Flags   += -D_DEBUG
 endif
 
-# If DISABLE_EXPENSIVE_CHECKS=1 is specified (make command line or configured),
-# then disable expensive checks by defining the appropriate preprocessor symbols.
+# If ENABLE_EXPENSIVE_CHECKS=1 is specified (make command line or 
+# configured), then enable expensive checks by defining the 
+# appropriate preprocessor symbols.
 ifdef ENABLE_EXPENSIVE_CHECKS
   BuildMode := $(BuildMode)+Checks
   CXX.Flags += -D_GLIBCXX_DEBUG