Simplify allocation in add_xroute.

xroute.c

@@ -104,9 +104,7 @@ add_xroute(unsigned char prefix[16], unsigned char plen,
     if(numxroutes >= maxxroutes) {
         struct xroute *new_xroutes;
         int n = maxxroutes < 1 ? 8 : 2 * maxxroutes;
-        new_xroutes = xroutes == NULL ?
-            malloc(n * sizeof(struct xroute)) :
-            realloc(xroutes, n * sizeof(struct xroute));
+        new_xroutes = realloc(xroutes, n * sizeof(struct xroute));
         if(new_xroutes == NULL)
             return -1;
         maxxroutes = n;