[SCSI] Remove ->pid field from scsi_cmnd

The pid field is a duplicate of the serial_number field and has been
scheduled for removal for a long time.  A few drivers were still using
it, so just change them to use serial_number instead.

Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index a5de1a8..07a7c2a 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -442,7 +442,7 @@
 #endif
 
 /* 
- * Assign a serial number and pid to the request for error recovery
+ * Assign a serial number to the request for error recovery
  * and debugging purposes.  Protected by the Host_Lock of host.
  */
 static inline void scsi_cmd_get_serial(struct Scsi_Host *host, struct scsi_cmnd *cmd)
@@ -450,10 +450,6 @@
 	cmd->serial_number = host->cmd_serial_number++;
 	if (cmd->serial_number == 0) 
 		cmd->serial_number = host->cmd_serial_number++;
-	
-	cmd->pid = host->cmd_pid++;
-	if (cmd->pid == 0)
-		cmd->pid = host->cmd_pid++;
 }
 
 /*