block: fix bad definition of BIO_RW_SYNC

We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO
and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before
213d9417fec62ef4c3675621b9364a667954d4dd.

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
diff --git a/include/linux/blktrace_api.h b/include/linux/blktrace_api.h
index 25379cb..6e91587 100644
--- a/include/linux/blktrace_api.h
+++ b/include/linux/blktrace_api.h
@@ -15,6 +15,7 @@
 	BLK_TC_WRITE	= 1 << 1,	/* writes */
 	BLK_TC_BARRIER	= 1 << 2,	/* barrier */
 	BLK_TC_SYNC	= 1 << 3,	/* sync IO */
+	BLK_TC_SYNCIO	= BLK_TC_SYNC,
 	BLK_TC_QUEUE	= 1 << 4,	/* queueing/merging */
 	BLK_TC_REQUEUE	= 1 << 5,	/* requeueing */
 	BLK_TC_ISSUE	= 1 << 6,	/* issue */