staging/rdma/hfi1: fix 0-day syntax error

Setting CONFIG_HFI1_DEBUG_SDMA_ORDER causes a syntax error:
sdma.c: In function ‘complete_tx’:
sdma.c:370: error: ‘txp’ undeclared (first use in
this function)
sdma.c:370: error: (Each undeclared identifier is reported only once
sdma.c:370: error: for each function it appears in.)

Adjust code under ifdef to reference the tx properly.
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>

drivers/staging/rdma/hfi1/sdma.c

@@ -367,10 +367,10 @@ static inline void complete_tx(struct sdma_engine *sde,
 	callback_t complete = tx->complete;
 
 #ifdef CONFIG_HFI1_DEBUG_SDMA_ORDER
-	trace_hfi1_sdma_out_sn(sde, txp->sn);
-	if (WARN_ON_ONCE(sde->head_sn != txp->sn))
+	trace_hfi1_sdma_out_sn(sde, tx->sn);
+	if (WARN_ON_ONCE(sde->head_sn != tx->sn))
 		dd_dev_err(sde->dd, "expected %llu got %llu\n",
-			   sde->head_sn, txp->sn);
+			   sde->head_sn, tx->sn);
 	sde->head_sn++;
 #endif
 	sdma_txclean(sde->dd, tx);