PCI/MSI: Rename "struct msi_chip" to "struct msi_controller"

"msi_chip" isn't very descriptive, so rename it to "msi_controller".  That
tells a little more about what it does and is already used in device tree
bindings.

No functional change.

[bhelgaas: changelog, change *only* the struct name so it's reviewable]
Suggested-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Yijing Wang <wangyijing@huawei.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index d9a92cf..0260f39 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -32,7 +32,7 @@
 
 int __weak arch_setup_msi_irq(struct pci_dev *dev, struct msi_desc *desc)
 {
-	struct msi_chip *chip = dev->bus->msi;
+	struct msi_controller *chip = dev->bus->msi;
 	int err;
 
 	if (!chip || !chip->setup_irq)
@@ -49,7 +49,7 @@
 
 void __weak arch_teardown_msi_irq(unsigned int irq)
 {
-	struct msi_chip *chip = irq_get_chip_data(irq);
+	struct msi_controller *chip = irq_get_chip_data(irq);
 
 	if (!chip || !chip->teardown_irq)
 		return;