ncr5380: Remove NCR5380_local_declare and NCR5380_setup macros

The NCR5380_local_declare and NCR5380_setup macros exist to define and
initialize a particular local variable, to provide the address of the
chip registers needed for the driver's implementation of its
NCR5380_read/write register access macros.

In cumana_1 and macscsi, these macros generate pointless code like this,
	struct Scsi_Host *_instance;
	_instance = instance;

In pas16, the use of NCR5380_read/write in pas16_hw_detect() requires that
the io_port local variable has been defined and initialized, but the
NCR5380_local_declare and NCR5380_setup macros can't be used for that
purpose because the Scsi_Host struct has not yet been instantiated.

Moreover, these macros were removed from atari_NCR5380.c long ago and
now they constitute yet another discrepancy between the two core driver
forks.

Remove these "optimizations".

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Tested-by: Ondrej Zary <linux@rainbow-software.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
diff --git a/drivers/scsi/dtc.h b/drivers/scsi/dtc.h
index 46483b2..07b0ac9 100644
--- a/drivers/scsi/dtc.h
+++ b/drivers/scsi/dtc.h
@@ -21,13 +21,8 @@
 #define NCR5380_implementation_fields \
     void __iomem *base
 
-#define NCR5380_local_declare() \
-    void __iomem *base
-
-#define NCR5380_setup(instance) \
-    base = ((struct NCR5380_hostdata *)(instance)->hostdata)->base
-
-#define DTC_address(reg) (base + DTC_5380_OFFSET + reg)
+#define DTC_address(reg) \
+	(((struct NCR5380_hostdata *)shost_priv(instance))->base + DTC_5380_OFFSET + reg)
 
 #define NCR5380_read(reg) (readb(DTC_address(reg)))
 #define NCR5380_write(reg, value) (writeb(value, DTC_address(reg)))