[SCSI] libosd: Define an osd_dev wrapper to retrieve the request_queue

libosd users that need to work with bios, must sometime use
the request_queue associated with the osd_dev. Make a wrapper for
that, and convert all in-tree users.

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/fs/exofs/inode.c b/fs/exofs/inode.c
index f79e8e5..77d0a29 100644
--- a/fs/exofs/inode.c
+++ b/fs/exofs/inode.c
@@ -59,10 +59,9 @@
 		struct inode *inode)
 {
 	struct exofs_sb_info *sbi = inode->i_sb->s_fs_info;
-	struct request_queue *req_q = sbi->s_dev->scsi_device->request_queue;
 
 	pcol->sbi = sbi;
-	pcol->req_q = req_q;
+	pcol->req_q = osd_request_queue(sbi->s_dev);
 	pcol->inode = inode;
 	pcol->expected_pages = expected_pages;