powerpc/52xx: Fix a resource leak in an error handling path

The error handling path of mpc52xx_lpbfifo_probe() has a request_irq()
that is not balanced by a corresponding free_irq().

Add the missing call, as already done in the remove function.

Fixes: 3c9059d7 ("powerpc/5200: add LocalPlus bus FIFO device driver")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/dec1496d46ccd5311d0f6e9f9ca4238be11bf6a6.1643440531.git.christophe.jaillet@wanadoo.fr

arch/powerpc/platforms/52xx/mpc52xx_lpbfifo.c

@@ -531,6 +531,7 @@ static int mpc52xx_lpbfifo_probe(struct platform_device *op)
  err_bcom_rx_irq:
 	bcom_gen_bd_rx_release(lpbfifo.bcom_rx_task);
  err_bcom_rx:
+	free_irq(lpbfifo.irq, &lpbfifo);
  err_irq:
 	iounmap(lpbfifo.regs);
 	lpbfifo.regs = NULL;