[SCSI] scsi_error thread exits in TASK_INTERRUPTIBLE state.

Found in the -rt patch set.  The scsi_error thread likely will be in the
TASK_INTERRUPTIBLE state upon exit.  This patch fixes this bug.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>