[SCSI] sg: increase sglist_len of the sg_scatter_hold structure

unsigned short is too small for sizeof(struct scatterlist) *
min(q->max_hw_segments, q->max_phys_segments).

This fixes memory leak with 4096 segments since 16 (likely sg size
with x86) * 4096 sets sglist_len to zero.

This might not happen without sg chaining support.
Signed-off-by: NFUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Acked-by: NDouglas Gilbert <dougg@torque.net>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/sg.c

@@ -114,7 +114,7 @@ static struct class_interface sg_interface = {
 
 typedef struct sg_scatter_hold { /* holding area for scsi scatter gather info */
 	unsigned short k_use_sg; /* Count of kernel scatter-gather pieces */
-	unsigned short sglist_len; /* size of malloc'd scatter-gather list ++ */
+	unsigned sglist_len; /* size of malloc'd scatter-gather list ++ */
 	unsigned bufflen;	/* Size of (aggregate) data buffer */
 	unsigned b_malloc_len;	/* actual len malloc'ed in buffer */
 	struct scatterlist *buffer;/* scatter list */