pata_legacy: fix a couple uninitialized variable bugs

The last byte of "pad" is used without being initialized.

Fixes: 55dba31 ("libata: update ->data_xfer hook for ATAPI")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>

Author: Dan Carpenter

drivers/ata/pata_legacy.c

@@ -352,7 +352,8 @@ static unsigned int pdc_data_xfer_vlb(struct ata_queued_cmd *qc,
 			iowrite32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
 
 		if (unlikely(slop)) {
-			__le32 pad;
+			__le32 pad = 0;
+
 			if (rw == READ) {
 				pad = cpu_to_le32(ioread32(ap->ioaddr.data_addr));
 				memcpy(buf + buflen - slop, &pad, slop);
@@ -742,7 +743,8 @@ static unsigned int vlb32_data_xfer(struct ata_queued_cmd *qc,
 			ioread32_rep(ap->ioaddr.data_addr, buf, buflen >> 2);
 
 		if (unlikely(slop)) {
-			__le32 pad;
+			__le32 pad = 0;
+
 			if (rw == WRITE) {
 				memcpy(&pad, buf + buflen - slop, slop);
 				iowrite32(le32_to_cpu(pad), ap->ioaddr.data_addr);