[IA64] Force error to surface in nofault code

Montecito behaves slightly differently than previous processors,
resulting in the MCA due to a failed PIO read to sometimes surfacing
outside the nofault code.  Adding an additional or and stop bits
ensures the MCA surfaces in the nofault code.
Signed-off-by: Russ Anderson <rja@sgi.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

arch/ia64/sn/kernel/xp_nofault.S

@@ -21,7 +21,8 @@
 xp_nofault_PIOR:
 	mov	r8=r0			// Stage a success return value
 	ld8.acq	r9=[r32];;		// PIO Read the specified register
-	adds	r9=1,r9			// Add to force a consume
+	adds	r9=1,r9;;		// Add to force consumption
+	or	r9=r9,r9;;		// Or to force consumption
 	br.ret.sptk.many b0;;		// Return success
 
 	.global xp_error_PIOR