breakp2.c, settrace(), cleanup #1/2

"save" command,
  reduce complexity from O(2) to O(1)

src/frontend/breakp2.c

@@ -49,7 +49,7 @@ com_save2(wordlist *wl, char *name)
 void
 settrace(wordlist *wl, int what, char *name)
 {
-    struct dbcomm *d, *td;
+    struct dbcomm *d, *last;
     char *s;
 
     if (!ft_curckt) {
@@ -57,6 +57,12 @@ settrace(wordlist *wl, int what, char *name)
         return;
     }
 
+    if (dbs)
+        for (last = dbs; last->db_next; last = last->db_next)
+            ;
+    else
+        last = NULL;
+
     while (wl) {
         s = cp_unquote(wl->wl_word);
         d = TMALLOC(struct dbcomm, 1);
@@ -96,13 +102,12 @@ settrace(wordlist *wl, int what, char *name)
 
         tfree(s);              /*DG avoid memoy leak */
 
-        if (dbs) {
-            for (td = dbs; td->db_next; td = td->db_next)
-                ;
-            td->db_next = d;
-        } else {
+        if (last)
+            last->db_next = d;
+        else
             ft_curckt->ci_dbs = dbs = d;
-        }
+
+        last = d;
 
         wl = wl->wl_next;
     }