[SCSI] osst: make all the buffer the same size

This simiplifies the buffer management; all the buffers in osst_buffer
become the same size. This is necessary to use the block layer API (sg
driver was modified in the same way) since the block layer API takes
the same size page frames instead of scatter gatter.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Willem Riede <osst@riede.org>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>

drivers/scsi/osst.c

@@ -5286,11 +5286,6 @@ static int enlarge_buffer(struct osst_buffer *STbuffer, int need_dma)
 		struct page *page = alloc_pages(priority, (OS_FRAME_SIZE - got <= PAGE_SIZE) ? 0 : order);
 		STbuffer->sg[segs].offset = 0;
 		if (page == NULL) {
-			if (OS_FRAME_SIZE - got <= (max_segs - segs) * b_size / 2 && order) {
-				b_size /= 2;  /* Large enough for the rest of the buffers */
-				order--;
-				continue;
-			}
 			printk(KERN_WARNING "osst :W: Failed to enlarge buffer to %d bytes.\n",
 						OS_FRAME_SIZE);
 #if DEBUG