blktap: Dequeue requests before completion.

The blk_end_request path won't dequeue implicitly any more.

Signed-off-by: Daniel Stodden <daniel.stodden@xxxxxxxxxx>

diff -r 666cc4c28bd7 -r 79d30c3f4345 drivers/xen/blktap/device.c
--- a/drivers/xen/blktap/device.c	Mon May 03 17:05:35 2010 -0700
+++ b/drivers/xen/blktap/device.c	Wed May 05 15:03:39 2010 -0700
@@ -795,11 +795,13 @@
 
 	while ((req = blk_peek_request(rq)) != NULL) {
 		if (!blk_fs_request(req)) {
+			blk_start_request(req);
 			__blk_end_request_cur(req, 0);
 			continue;
 		}
 
 		if (blk_barrier_rq(req)) {
+			blk_start_request(req);
 			__blk_end_request_cur(req, 0);
 			continue;
 		}
@@ -882,7 +884,7 @@
 	return;
 
 fail:
-	while ((req = blk_peek_request(rq))) {
+	while ((req = blk_fetch_request(rq))) {
 		BTERR("device closed: failing secs %llu - %llu\n",
 		      (unsigned long long)blk_rq_pos(req),
 		      (unsigned long long)blk_rq_pos(req) + blk_rq_sectors(req));