PCI/AER: Remove "extern" from function declarations

We had an inconsistent mix of using and omitting the "extern" keyword
on function declarations in header files.  This removes them all.

[bhelgaas: split out from "move AER severity defines" patch]
Signed-off-by: Betty Dall <betty.dall@hp.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>

include/linux/aer.h

@@ -35,9 +35,9 @@ struct aer_capability_regs {
 
 #if defined(CONFIG_PCIEAER)
 /* pci-e port driver needs this function to enable aer */
-extern int pci_enable_pcie_error_reporting(struct pci_dev *dev);
-extern int pci_disable_pcie_error_reporting(struct pci_dev *dev);
-extern int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
+int pci_enable_pcie_error_reporting(struct pci_dev *dev);
+int pci_disable_pcie_error_reporting(struct pci_dev *dev);
+int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev);
 #else
 static inline int pci_enable_pcie_error_reporting(struct pci_dev *dev)
 {
@@ -53,10 +53,10 @@ static inline int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
 }
 #endif
 
-extern void cper_print_aer(const char *prefix, struct pci_dev *dev,
-			   int cper_severity, struct aer_capability_regs *aer);
-extern int cper_severity_to_aer(int cper_severity);
-extern void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
-			      int severity);
+void cper_print_aer(const char *prefix, struct pci_dev *dev, int cper_severity,
+		    struct aer_capability_regs *aer);
+int cper_severity_to_aer(int cper_severity);
+void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
+		       int severity);
 #endif //_AER_H_