atari_NCR5380: Move static co-routine variables to host data

Unlike NCR5380.c, the atari_NCR5380.c core driver is limited to a single
instance because co-routine state is stored globally.

Fix this by removing the static scsi host pointer. For the co-routine,
obtain this pointer from the work_struct pointer instead. For the interrupt
handler, obtain it from the dev_id argument.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Tested-by: Michael Schmitz <schmitzmic@gmail.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/scsi/NCR5380.h

@@ -283,6 +283,8 @@ struct NCR5380_hostdata {
 	int read_overruns;                /* number of bytes to cut from a
 	                                   * transfer to handle chip overruns */
 	int retain_dma_intr;
+	struct work_struct main_task;
+	volatile int main_running;
 #ifdef SUPPORT_TAGS
 	struct tag_alloc TagAlloc[8][8];	/* 8 targets and 8 LUNs */
 #endif