[SCSI] use a completion in scsi_send_eh_cmnd

scsi_send_eh_cmnd currently uses a semaphore and an overload of eh_timer
to either get a completion for a command for a timeout.
Switch to using a completion and wait_for_completion_timeout to simply
the code and not having to deal with the races ourselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 9984d3f..6cbb198 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -7,6 +7,7 @@
 #include <linux/workqueue.h>
 
 struct block_device;
+struct completion;
 struct module;
 struct scsi_cmnd;
 struct scsi_device;
@@ -467,8 +468,8 @@
 
 	struct list_head	eh_cmd_q;
 	struct task_struct    * ehandler;  /* Error recovery thread. */
-	struct semaphore      * eh_action; /* Wait for specific actions on the
-                                          host. */
+	struct completion     * eh_action; /* Wait for specific actions on the
+					      host. */
 	wait_queue_head_t       host_wait;
 	struct scsi_host_template *hostt;
 	struct scsi_transport_template *transportt;