fix warnings.

C/c_interface.c

@@ -4006,7 +4006,6 @@ YAP_IsNumberedVariable(Term t) {
 
 X_API size_t
 YAP_ExportTerm(Term inp, char * buf, size_t len) {
-  size_t res;
   if (!len)
     return 0;
   return Yap_ExportTerm(inp, buf, len, current_arity());

library/lammpi/prologterms2c.c

@@ -203,7 +203,6 @@ term2string(char *const ptr, size_t *size, const YAP_Term t) {
 YAP_Term 
 string2term(char *const ptr,const size_t *size) {
   YAP_Term t;
-  struct buffer_ds b;
 
   t = YAP_ImportTerm( ptr );
   if ( t==FALSE ) {