PCI: dwc: Correct msi_irq condition in dw_pcie_free_msi()

PCI: dwc: Correct msi_irq condition in dw_pcie_free_msi()

The dwc-based drivers set pp->msi_irq to -ENODEV if they do not want the
dwc core to do anything with pp->msi_irq.

dw_pcie_host_init() sets the handler and data when "pp->msi_irq > 0", so
use the same condition when removing the handler and data in
dw_pcie_free_msi().

Link: https://lore.kernel.org/r/20220707134733.2436629-2-dmitry.baryshkov@linaro.org
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>