Squish various compiler warnings

* CPP's defined() is UB outside of a #if line
* Use (void)! cast to prevent recent GCCs & glibc from warning
  about ignoring the return status from chdir()

modules/ca/src/client/caRepeater.cpp

@@ -90,7 +90,7 @@ int main(int argc, char* argv[])
     (void)detachinout;
 #endif
 
-    chdir ( "/" );
+    (void)! chdir ( "/" );
     ca_repeater ();
     return ( 0 );
 }