net: remove muldiv64()

muldiv64() is used to convert nanoseconds to microseconds.

    x = muldiv64(qemu_clock_get_ns(..), 1000000, get_ticks_per_sec());

As  get_ticks_per_sec() is 10^9, it can be replaced by:

    x = qemu_clock_get_us(..);
Signed-off-by: NLaurent Vivier <lvivier@redhat.com>
Reviewed-by: NStefan Hajnoczi <stefanha@redhat.com>

net/dump.c

@@ -69,7 +69,7 @@ static ssize_t dump_receive(NetClientState *nc, const uint8_t *buf, size_t size)
         return size;
     }
 
-    ts = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), 1000000, get_ticks_per_sec());
+    ts = qemu_clock_get_us(QEMU_CLOCK_VIRTUAL);
     caplen = size > s->pcap_caplen ? s->pcap_caplen : size;
 
     hdr.ts.tv_sec = ts / 1000000 + s->start_ts;