[SCSI] export command allocation and freeing functions independently of the host

This is needed by things like USB storage that want to set up static
commands for later use at start of day.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index b260be6..8d20e60 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -130,6 +130,9 @@
 extern int scsi_dma_map(struct scsi_cmnd *cmd);
 extern void scsi_dma_unmap(struct scsi_cmnd *cmd);
 
+struct scsi_cmnd *scsi_allocate_command(gfp_t gfp_mask);
+void scsi_free_command(gfp_t gfp_mask, struct scsi_cmnd *cmd);
+
 static inline unsigned scsi_sg_count(struct scsi_cmnd *cmd)
 {
 	return cmd->sdb.table.nents;