Fix some Krazy warnings about non-const ref iterator.

Change-Id: I1c78f5f5a7174002cd25bea109d5fe795530cdb5
Reviewed-by: Daniel Teske <daniel.teske@digia.com>

src/libs/utils/environment.cpp

@@ -258,7 +258,7 @@ QString Environment::searchInPath(const QString &executable,
         }
     }
 
-    foreach (QString dir, additionalDirs) {
+    foreach (const QString &dir, additionalDirs) {
         QString tmp = searchInDirectory(execs, dir);
         if (!tmp.isEmpty())
             return tmp;