Pbslbadisk is harmlessly using the wrong instruction here.
This change makes it match pbslba.s.

Notes:
Mon Mar 17 16:35:48 EDT 2008 geoff
    this is only a debugging pbs anyway.


Reference: /n/sources/patch/applied/pbsdisklba-sbpwi
Date: Sat Feb 23 00:53:15 CET 2008
Signed-off-by: micah@stetsonnet.org
Reviewed-by: geoff

--- /sys/src/boot/pc/pbsdisklba.s	Sat Feb 23 00:52:32 2008
+++ /sys/src/boot/pc/pbsdisklba.s	Sat Feb 23 00:52:29 2008
@@ -111,7 +111,7 @@
 
 					/* rCX contains 0x0001 */
 	SBPWI(0x0010, Xdap+0)		/* reserved + packet size */
-	SBPWI(rCX, Xdap+2)		/* reserved + # of blocks to transfer */
+	SBPW(rCX, Xdap+2)		/* reserved + # of blocks to transfer */
 
 	DEC(rCX)
 	SBPW(rCX, Xdap+12)