Revert "The TODO seems to be DONE"

Actually I am not sure at all.

This reverts commit 3b56738d.

bin/fixincludeguards.sh

@@ -11,6 +11,12 @@
 # a) fixincludeguards.sh header.hxx
 # b) find . -name *.hxx -or -name *.h | xargs sh fixincludeguards.sh
 
+# TODO: This doesn't fix wrong #endif comments, like:
+# #ifndef FOO_BAR_HXX
+# #define FOO_BAR_HXX
+# ...
+# #endif // OTHER_BAR_HXX
+
 guard_prefix="INCLUDED_"
 
 for fn in "$@"; do