ata: fixup ATA_PROT_NODATA

The taskfile protocol is a numeric value, and can not be ORed.  Currently
this is harmless as the protocol is always zeroed before, but if it ever
has a non-zero value the ORing would create incorrect results.

Signed-off-by: Hannes Reinecke <hare@suse.de>
[hch: updated patch description]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
diff --git a/drivers/ata/libata-core.c b/drivers/ata/libata-core.c
index f5eb07e..522848a 100644
--- a/drivers/ata/libata-core.c
+++ b/drivers/ata/libata-core.c
@@ -1238,7 +1238,7 @@
 	} else
 		tf.command = ATA_CMD_READ_NATIVE_MAX;
 
-	tf.protocol |= ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	tf.device |= ATA_LBA;
 
 	err_mask = ata_exec_internal(dev, &tf, NULL, DMA_NONE, NULL, 0, 0);
@@ -1297,7 +1297,7 @@
 		tf.device |= (new_sectors >> 24) & 0xf;
 	}
 
-	tf.protocol |= ATA_PROT_NODATA;
+	tf.protocol = ATA_PROT_NODATA;
 	tf.device |= ATA_LBA;
 
 	tf.lbal = (new_sectors >> 0) & 0xff;