PCI/ASPM: Add pci_disable_link_state_locked() lockdep assert

Add a lockdep assert to pci_disable_link_state_locked() which should only
be called with a pci_bus_sem read lock held.

Link: https://lore.kernel.org/r/20231128081512.19387-7-johan+linaro@kernel.org
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
[bhelgaas: include function name in subject, commit log]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>

drivers/pci/pcie/aspm.c

@@ -1090,6 +1090,8 @@ static int __pci_disable_link_state(struct pci_dev *pdev, int state, bool locked
 
 int pci_disable_link_state_locked(struct pci_dev *pdev, int state)
 {
+	lockdep_assert_held_read(&pci_bus_sem);
+
 	return __pci_disable_link_state(pdev, state, true);
 }
 EXPORT_SYMBOL(pci_disable_link_state_locked);