codemaker: fix^2 invalid string index access

...originally the past-the-end checks in destination where always true, and thus
happend to work as intended for empty destionation, but
614e04019a broke that, so calling cppumaker w/o
-O was broken now.

Change-Id: I8d41dfe8d4c12e4a73a9782d4d5e7c9fa4d9df81

codemaker/source/codemaker/global.cxx

@@ -87,11 +87,8 @@ OString createFileNameFromType( const OString& destination,
     length += prefix.getLength() + type.getLength() + postfix.getLength();
 
     sal_Bool withSeparator = sal_False;
-    if (!destination.isEmpty() &&
-        destination[destination.getLength() - 1] != '\\' &&
-        destination[destination.getLength() - 1] != '/' &&
-        type[0] != '\\' &&
-        type[0] != '/')
+    if (!(destination.endsWith("\\") || destination.endsWith("/"))
+        && !(type.startsWith("\\") || type.startsWith("/")))
     {
         length++;
         withSeparator = sal_True;