QTzTimeZonePrivate: don't assume int is a 4-byte type

It probably is today, but when the I/O we're doing is explicit about
how many bytes it eats, make sure we're using an explicitly 4-byte
type, qint32.

Change-Id: I48a35fe58043368cdfd096e2628bba410d94ceaa
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

src/corelib/tools/qtimezoneprivate_tz.cpp

@@ -199,7 +199,7 @@ static QVector<QTzTransition> parseTzTransitions(QDataStream &ds, int tzh_timecn
         }
     } else {
         // Parse tzh_timecnt x 4-byte transition times
-        int val;
+        qint32 val;
         for (int i = 0; i < tzh_timecnt && ds.status() == QDataStream::Ok; ++i) {
             ds >> val;
             transitions[i].tz_time = val;