x86/pci/intel_mid_pci: Fix PCIBIOS_* return code handling

intel_mid_pci_irq_enable() uses pci_read_config_byte() that returns
PCIBIOS_* codes. The error handling, however, assumes the codes are
normal errnos because it checks for < 0.

intel_mid_pci_irq_enable() also returns the PCIBIOS_* code back to the
caller but the function is used as the (*pcibios_enable_irq) function
which should return normal errnos.

Convert the error check to plain non-zero check which works for
PCIBIOS_* return codes and convert the PCIBIOS_* return code using
pcibios_err_to_errno() into normal errno before returning it.

Fixes: 5b395e2b ("x86/platform/intel-mid: Make IRQ allocation a bit more flexible")
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20240527125538.13620-2-ilpo.jarvinen@linux.intel.com

arch/x86/pci/intel_mid_pci.c

@@ -233,9 +233,9 @@ static int intel_mid_pci_irq_enable(struct pci_dev *dev)
 		return 0;
 
 	ret = pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &gsi);
-	if (ret < 0) {
+	if (ret) {
 		dev_warn(&dev->dev, "Failed to read interrupt line: %d\n", ret);
-		return ret;
+		return pcibios_err_to_errno(ret);
 	}
 
 	id = x86_match_cpu(intel_mid_cpu_ids);