5261 libm should stop using synonyms.h

@@ -24,12 +24,12 @@
 /*
  * Copyright 2005 Sun Microsystems, Inc.  All rights reserved.
  * Use is subject to license terms.
  */
 
-#pragma weak erff = __erff
-#pragma weak erfcf = __erfcf
+#pragma weak __erff = erff
+#pragma weak __erfcf = erfcf
 
 #include "libm.h"
 
 #if defined(__i386) && !defined(__amd64)
 extern int __swapRP(int);