block: pass block dev not num to read/write/erase()

This will allow the implementation to make use of data in the block_dev
structure beyond the base device number. This will be useful so that eMMC
block devices can encompass the HW partition ID rather than treating this
out-of-band. Equally, the existence of the priv field is crying out for
this patch to exist.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Tom Rini <trini@konsulko.com>

lib/gunzip.c

@@ -231,8 +231,7 @@ int gzwrite(unsigned char *src, int len,
 			gzwrite_progress(iteration++,
 					 totalfilled,
 					 szexpected);
-			blocks_written = dev->block_write(dev->dev,
-							  outblock,
+			blocks_written = dev->block_write(dev, outblock,
 							  writeblocks,
 							  writebuf);
 			outblock += blocks_written;