net: 3com: 3c59x: fix possible null dereference in vortex_probe1()

pdev can be null and free_ring: can be called in 1297 with a null
pdev.

Fixes: 55c8261 ("3c59x: convert to generic DMA API")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://patch.msgid.link/20260106094731.25819-2-fourier.thomas@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Thomas-fourier

drivers/net/ethernet/3com/3c59x.c

@@ -1473,7 +1473,7 @@ static int vortex_probe1(struct device *gendev, void __iomem *ioaddr, int irq,
 		return 0;
 
 free_ring:
-	dma_free_coherent(&pdev->dev,
+	dma_free_coherent(gendev,
 		sizeof(struct boom_rx_desc) * RX_RING_SIZE +
 		sizeof(struct boom_tx_desc) * TX_RING_SIZE,
 		vp->rx_ring, vp->rx_ring_dma);