dselect: Move total_width initialization from derived classes to baselist

dselect/baselist.cc

@@ -243,6 +243,9 @@ baselist::baselist(keybindings *kb) {
   nitems= 0;
 
   gap_width = 1;
+  total_width = TOTAL_LIST_WIDTH;
+  if (total_width < COLS)
+    total_width = COLS;
 
   xmax= -1;
   list_height=0; info_height=0;

dselect/methlist.cc

@@ -63,10 +63,6 @@ void methodlist::setwidths() {
   name_width= 14;
   name_column= status_width + gap_width;
   description_column= name_column + name_width + gap_width;
-
-  total_width= TOTAL_LIST_WIDTH;
-  if (total_width < COLS)
-    total_width= COLS;
   description_width= total_width - description_column;
 }
 

dselect/pkgdisplay.cc

@@ -181,9 +181,6 @@ void packagelist::setwidths() {
     internerr("unknown versiondisplayopt %d in setwidths", versiondisplayopt);
   }
 
-  total_width= TOTAL_LIST_WIDTH;
-  if (total_width < COLS)
-    total_width= COLS;
   description_width= total_width - description_column;
 }