[SCSI] st: fix kernel BUG at include/linux/scatterlist.h:59!

This is caused by a missing scatterlist initialisation (it only shows
up when sg list handling debugging is turned on).

Signed-off-by: FUJITA Tomonori <[e-mail]>
Cc: Kai Makisara <[e-mail]>
Signed-off-by: James Bottomley <[e-mail]>

drivers/scsi/st.c

···
 
 	tb->dma = need_dma;
 	tb->buffer_size = got;
+	sg_init_table(tb->sg, max_sg);
 
 	return tb;
 }