[SCSI] st: remove unused st_buffer.in_use

I noticed that in_use in st_buffer is not used. The patch below
against 2.6.17-rc3 removes it, assuming there is no future use for it.
It was tested in a sparc SS20 with a DLT4000.

Signed-off-by: Martin Habets <[e-mail]>
Acked-by: Kai M�kisara <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/st.c

···
 	tb->use_sg = max_sg;
 	tb->frp = (struct st_buf_fragment *)(&(tb->sg[0]) + max_sg);
 
-	tb->in_use = 1;
 	tb->dma = need_dma;
 	tb->buffer_size = got;
 

drivers/scsi/st.h

···
 
 /* The tape buffer descriptor. */
 struct st_buffer {
-	unsigned char in_use;
 	unsigned char dma;	/* DMA-able buffer */
 	unsigned char do_dio;   /* direct i/o set up? */
 	int buffer_size;