[ARM] Fix an rpc_defconfig regression

Fix:

  CC      drivers/scsi/arm/powertec.o
In file included from drivers/scsi/arm/powertec.c:29:
drivers/scsi/arm/scsi.h: In function 'next_SCp':
drivers/scsi/arm/scsi.h:42: error: 'struct scatterlist' has no member named 'page'
drivers/scsi/arm/scsi.h: In function 'init_SCp':
drivers/scsi/arm/scsi.h:80: error: 'struct scatterlist' has no member named 'page'
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

drivers/scsi/arm/scsi.h

@@ -38,9 +38,7 @@ static inline int next_SCp(struct scsi_pointer *SCp)
 	if (ret) {
 		SCp->buffer++;
 		SCp->buffers_residual--;
-		SCp->ptr = (char *)
-			 (page_address(SCp->buffer->page) +
-			  SCp->buffer->offset);
+		SCp->ptr = sg_virt(SCp->buffer);
 		SCp->this_residual = SCp->buffer->length;
 	} else {
 		SCp->ptr = NULL;
@@ -76,9 +74,7 @@ static inline void init_SCp(struct scsi_cmnd *SCpnt)
 
 		SCpnt->SCp.buffer = (struct scatterlist *) SCpnt->request_buffer;
 		SCpnt->SCp.buffers_residual = SCpnt->use_sg - 1;
-		SCpnt->SCp.ptr = (char *)
-			 (page_address(SCpnt->SCp.buffer->page) +
-			  SCpnt->SCp.buffer->offset);
+		SCpnt->SCp.ptr = sg_virt(SCpnt->SCp.buffer);
 		SCpnt->SCp.this_residual = SCpnt->SCp.buffer->length;
 		SCpnt->SCp.phase = SCpnt->request_bufflen;