dmaengine: ti: edma: Remove 'Assignment in if condition'

While the compiler does not have problem with how it is implemented,
checkpatch does give en ERROR for this arrangement.

Signed-off-by: Peter Ujfalusi <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Vinod Koul <[e-mail]>

drivers/dma/ti/edma.c

···
 				      struct dma_tx_state *txstate)
 {
 	struct edma_chan *echan = to_edma_chan(chan);
-	struct virt_dma_desc *vdesc;
 	struct dma_tx_state txstate_tmp;
 	enum dma_status ret;
 	unsigned long flags;
···
 	if (!txstate)
 		txstate = &txstate_tmp;
 
-	txstate->residue = 0;
 	spin_lock_irqsave(&echan->vchan.lock, flags);
-	if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie)
+	if (echan->edesc && echan->edesc->vdesc.tx.cookie == cookie) {
 		txstate->residue = edma_residue(echan->edesc);
-	else if ((vdesc = vchan_find_desc(&echan->vchan, cookie)))
-		txstate->residue = to_edma_desc(&vdesc->tx)->residue;
+	} else {
+		struct virt_dma_desc *vdesc = vchan_find_desc(&echan->vchan,
+							      cookie);
+
+		if (vdesc)
+			txstate->residue = to_edma_desc(&vdesc->tx)->residue;
+		else
+			txstate->residue = 0;
+	}
 
 	/*
 	 * Mark the cookie completed if the residue is 0 for non cyclic