PCI: xgene-msi: Return negative -EINVAL in xgene_msi_handler_setup()

There is a typo so we accidentally return positive EINVAL instead of
negative -EINVAL. Add the missing '-' character.

Fixes: 6aceb36 ("PCI: xgene-msi: Restructure handler setup/teardown")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://patch.msgid.link/aIzCbVd93ivPinne@stanley.mountain

Author: Dan Carpenter

drivers/pci/controller/pci-xgene-msi.c

@@ -311,7 +311,7 @@ static int xgene_msi_handler_setup(struct platform_device *pdev)
 		msi_val = xgene_msi_int_read(xgene_msi, i);
 		if (msi_val) {
 			dev_err(&pdev->dev, "Failed to clear spurious IRQ\n");
-			return EINVAL;
+			return -EINVAL;
 		}
 
 		irq = platform_get_irq(pdev, i);