Explicitly cast when dividing ints then implicitly casting to double.

Coverity thinks that when we do "double x = int1/int2;", we probably
meant "double x = ((double)int1) / int2;".  In these cases, we
didn't.

[Coverity CID 1232089 and 1232090]

src/or/circuitstats.c

@@ -1371,10 +1371,11 @@ circuit_build_times_network_check_changed(circuit_build_times_t *cbt)
   }
   cbt->liveness.after_firsthop_idx = 0;
 
+#define MAX_TIMEOUT ((int32_t) (INT32_MAX/2))
   /* Check to see if this has happened before. If so, double the timeout
    * to give people on abysmally bad network connections a shot at access */
   if (cbt->timeout_ms >= circuit_build_times_get_initial_timeout()) {
-    if (cbt->timeout_ms > INT32_MAX/2 || cbt->close_ms > INT32_MAX/2) {
+    if (cbt->timeout_ms > MAX_TIMEOUT || cbt->close_ms > MAX_TIMEOUT) {
       log_warn(LD_CIRC, "Insanely large circuit build timeout value. "
               "(timeout = %fmsec, close = %fmsec)",
                cbt->timeout_ms, cbt->close_ms);
@@ -1386,6 +1387,7 @@ circuit_build_times_network_check_changed(circuit_build_times_t *cbt)
     cbt->close_ms = cbt->timeout_ms
                   = circuit_build_times_get_initial_timeout();
   }
+#undef MAX_TIMEOUT
 
   cbt_control_event_buildtimeout_set(cbt, BUILDTIMEOUT_SET_EVENT_RESET);
 

src/or/routerlist.c

@@ -1809,7 +1809,7 @@ scale_array_elements_to_u64(u64_dbl_t *entries, int n_entries,
   double scale_factor;
   int i;
   /* big, but far away from overflowing an int64_t */
-#define SCALE_TO_U64_MAX (INT64_MAX / 4)
+#define SCALE_TO_U64_MAX ((int64_t) (INT64_MAX / 4))
 
   for (i = 0; i < n_entries; ++i)
     total += entries[i].dbl;