[SCSI] libosd: osd_req_{read,write}_kern new API

By popular demand, define usefull wrappers for osd_req_read/write
that recieve kernel pointers. All users had their own.

Also remove these from exofs

Signed-off-by: Boaz Harrosh <bharrosh@panasas.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

include/scsi/osd_initiator.h

@@ -364,6 +364,8 @@ void osd_req_remove_object(struct osd_request *or, struct osd_obj_id *);
 
 void osd_req_write(struct osd_request *or,
 	const struct osd_obj_id *, struct bio *data_out, u64 offset);
+int osd_req_write_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void *buff, u64 len);
 void osd_req_append(struct osd_request *or,
 	const struct osd_obj_id *, struct bio *data_out);/* NI */
 void osd_req_create_write(struct osd_request *or,
@@ -379,6 +381,8 @@ void osd_req_flush_object(struct osd_request *or,
 
 void osd_req_read(struct osd_request *or,
 	const struct osd_obj_id *, struct bio *data_in, u64 offset);
+int osd_req_read_kern(struct osd_request *or,
+	const struct osd_obj_id *obj, u64 offset, void *buff, u64 len);
 
 /*
  * Root/Partition/Collection/Object Attributes commands