The select not the original parameter get the file/line info.

When taking a variable part select of a parameter we need to
give file and line information to the select not the parameter.
(cherry picked from commit 0106578fb6)

elab_expr.cc

@@ -2748,7 +2748,7 @@ NetExpr* PEIdent::elaborate_expr_param_(Design*des,
 		       evaluate the select at run-time. */
 
 		  NetESelect*stmp = new NetESelect(tmp, mtmp, 1);
-		  tmp->set_line(*this);
+		  stmp->set_line(*this);
 		  tmp = stmp;
 	    }