dpkg: Move varbuf related calls close together in setselections()

It's easier to read if the varbuf calls affecting the same variable are
close together, rather than dispersed around in the code.

src/select.c

@@ -95,36 +95,40 @@ void setselections(const char *const *argv) {
 
   lno= 1;
   for (;;) {
-    varbuf_reset(&namevb);
-    varbuf_reset(&selvb);
     do { c= getchar(); if (c == '\n') lno++; } while (c != EOF && isspace(c));
     if (c == EOF) break;
     if (c == '#') {
       do { c= getchar(); if (c == '\n') lno++; } while (c != EOF && c != '\n');
       continue;
     }
+
+    varbuf_reset(&namevb);
     while (!isspace(c)) {
       varbuf_add_char(&namevb, c);
       c= getchar();
       if (c == EOF) ohshit(_("unexpected eof in package name at line %d"),lno);
       if (c == '\n') ohshit(_("unexpected end of line in package name at line %d"),lno);
     }
+    varbuf_add_char(&namevb, '\0');
+
     while (c != EOF && isspace(c)) {
       c= getchar();
       if (c == EOF) ohshit(_("unexpected eof after package name at line %d"),lno);
       if (c == '\n') ohshit(_("unexpected end of line after package name at line %d"),lno);
     }
+
+    varbuf_reset(&selvb);
     while (c != EOF && !isspace(c)) {
       varbuf_add_char(&selvb, c);
       c= getchar();
     }
+    varbuf_add_char(&selvb, '\0');
+
     while (c != EOF && c != '\n') {
       c= getchar();
       if (!isspace(c))
         ohshit(_("unexpected data after package and selection at line %d"),lno);
     }
-    varbuf_add_char(&namevb, '\0');
-    varbuf_add_char(&selvb, '\0');
     e = pkg_name_is_illegal(namevb.buf, NULL);
     if (e) ohshit(_("illegal package name at line %d: %.250s"),lno,e);