Reduce size of congestion control next_*_event fields.

Since these are derived from the number of SENDMEs in a cwnd/cc update,
and a cwnd should not exceed ~10k, there's plenty of room in uint16_t
for them, even if the network gets significantly faster.

src/core/or/congestion_control_nola.c

@@ -108,7 +108,7 @@ congestion_control_nola_process_sendme(congestion_control_t *cc,
                "CC TOR_NOLA: Circuit %d "
                "CWND: %"PRIu64", "
                "INFL: %"PRIu64", "
-               "NCCE: %"PRIu64", "
+               "NCCE: %"PRIu16", "
                "SS: %d",
              CONST_TO_ORIGIN_CIRCUIT(circ)->global_identifier,
              cc->cwnd,
@@ -121,7 +121,7 @@ congestion_control_nola_process_sendme(congestion_control_t *cc,
                "CC TOR_NOLA: Circuit %"PRIu64":%d "
                "CWND: %"PRIu64", "
                "INFL: %"PRIu64", "
-               "NCCE: %"PRIu64", "
+               "NCCE: %"PRIu16", "
                "SS: %d",
              CONST_TO_OR_CIRCUIT(circ)->p_chan->global_identifier,
              CONST_TO_OR_CIRCUIT(circ)->p_circ_id,

src/core/or/congestion_control_st.h

@@ -158,11 +158,11 @@ struct congestion_control_t {
    * It is also reset to 0 immediately whenever the circuit's orconn is
    * blocked, and when a previously blocked orconn is unblocked.
    */
-  uint64_t next_cc_event;
+  uint16_t next_cc_event;
 
   /** Counts down until we process a cwnd worth of SENDME acks.
    * Used to track full cwnd status. */
-  uint64_t next_cwnd_event;
+  uint16_t next_cwnd_event;
 
   /** Are we in slow start? */
   bool in_slow_start;

src/core/or/congestion_control_westwood.c

@@ -201,7 +201,7 @@ congestion_control_westwood_process_sendme(congestion_control_t *cc,
                  "CC: TOR_WESTWOOD Circuit %d "
                  "CWND: %"PRIu64", "
                  "INFL: %"PRIu64", "
-                 "NCCE: %"PRIu64", "
+                 "NCCE: %"PRIu16", "
                  "WRTT: %"PRIu64", "
                  "WSIG: %"PRIu64", "
                  "SS: %d",
@@ -218,7 +218,7 @@ congestion_control_westwood_process_sendme(congestion_control_t *cc,
                  "CC: TOR_WESTWOOD Circuit %"PRIu64":%d "
                  "CWND: %"PRIu64", "
                  "INFL: %"PRIu64", "
-                 "NCCE: %"PRIu64", "
+                 "NCCE: %"PRIu16", "
                  "WRTT: %"PRIu64", "
                  "WSIG: %"PRIu64", "
                  "SS: %d",