uClibc should actually support va_copy

SVN-Revision: 10906

include/site/linux-uclibc

@@ -64,5 +64,5 @@ ac_cv_uint=yes
 ac_cv_uint64_t=yes
 ac_cv_ulong=yes
 ac_cv_ushort=yes
-ac_cv_va_copy=no
+ac_cv_va_copy=C99
 ac_cv_va_val_copy=yes