PCI: endpoint: pci-epf-vntb: reduce several globals to statics

sparse reports
drivers/pci/endpoint/functions/pci-epf-vntb.c:975:5: warning: symbol 'pci_read' was not declared. Should it be static?
drivers/pci/endpoint/functions/pci-epf-vntb.c:984:5: warning: symbol 'pci_write' was not declared. Should it be static?
drivers/pci/endpoint/functions/pci-epf-vntb.c:989:16: warning: symbol 'vpci_ops' was not declared. Should it be static?

These functions and variables are only used in pci-epf-vntb.c, so their storage
class specifiers should be static.

Fixes: ff32fac ("NTB: EPF: support NTB transfer between PCI RC and EP connection")
Signed-off-by: Tom Rix <trix@redhat.com>
Acked-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

drivers/pci/endpoint/functions/pci-epf-vntb.c

@@ -978,7 +978,7 @@ static u32 pci_space[] = {
 	0,		/*Max Lat, Min Gnt, interrupt pin, interrupt line*/
 };
 
-int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
+static int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *val)
 {
 	if (devfn == 0) {
 		memcpy(val, ((u8 *)pci_space) + where, size);
@@ -987,12 +987,12 @@ int pci_read(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 *
 	return PCIBIOS_DEVICE_NOT_FOUND;
 }
 
-int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
+static int pci_write(struct pci_bus *bus, unsigned int devfn, int where, int size, u32 val)
 {
 	return 0;
 }
 
-struct pci_ops vpci_ops = {
+static struct pci_ops vpci_ops = {
 	.read = pci_read,
 	.write = pci_write,
 };