[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/include/scsi/scsi_host.h b/include/scsi/scsi_host.h
index 5b79697..7d210cd 100644
--- a/include/scsi/scsi_host.h
+++ b/include/scsi/scsi_host.h
@@ -580,7 +580,7 @@
 	 * Used to assign serial numbers to the cmds.
 	 * Protected by the host lock.
 	 */
-	unsigned long cmd_serial_number, cmd_pid; 
+	unsigned long cmd_serial_number;
 	
 	unsigned active_mode:2;
 	unsigned unchecked_isa_dma:1;