[SCSI] iscsi_tcp: make padbuf non-static

virt_to_page() call should not be used on kernel text and data
addresses. virt_to_page() is used by sg_init_one(). So change padbuf
to be allocated within iscsi_segment.

Signed-off-by: Karen Xie <[e-mail]>
Acked-by: Mike Christie <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/libiscsi_tcp.c

···
 			   struct iscsi_segment *segment, int recv,
 			   unsigned copied)
 {
-	static unsigned char padbuf[ISCSI_PAD_LEN];
 	struct scatterlist sg;
 	unsigned int pad;
 
···
 			debug_tcp("consume %d pad bytes\n", pad);
 			segment->total_size += pad;
 			segment->size = pad;
-			segment->data = padbuf;
+			segment->data = segment->padbuf;
 			return 0;
 		}
 	}

include/scsi/libiscsi_tcp.h

···
 	unsigned int		total_copied;
 
 	struct hash_desc	*hash;
+	unsigned char		padbuf[ISCSI_PAD_LEN];
 	unsigned char		recv_digest[ISCSI_DIGEST_SIZE];
 	unsigned char		digest[ISCSI_DIGEST_SIZE];
 	unsigned int		digest_len;