The conversion to the new hotplug state machine introduced a regression where a successful hotplug registration would be treated as an error, effectively disabling the MSI driver forever. Fix it by doing the proper check on the return value. Fixes: 9c248f8896e6 ("PCI/xgene-msi: Convert to hotplug state machine") Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Tested-by: Duc Dang <dhdang@apm.com> CC: Thomas Gleixner <tglx@linutronix.de> CC: stable@vger.kernel.org