Be very generous with timeouts for synchronize cache. We may wait a very long

time in the cases where it really sends the drive out to lunch, but it also
allows us to catch very wierd edge cases of strange drives that might take
a very long time (emulated disk drives over a network, e.g.).

sys/cam/scsi/scsi_da.c

@@ -1680,7 +1680,7 @@ dashutdown(void * arg, int howto)
 				       /*begin_lba*/0, /* whole disk */
 				       /*lb_count*/0,
 				       SSD_FULL_SIZE,
-				       5 * 60 * 1000);
+				       60 * 60 * 1000);
 
 		xpt_polled_action(&ccb);