[PATCH -next] vgaarb.h: fix build warnings

[Randy Dunlap]

From: Randy Dunlap <rdunlap at xenotime.net>

Fix build warnings by providing a struct stub since no fields of
the struct are used:

include/linux/vgaarb.h:66:9: warning: 'struct pci_dev' declared inside parameter list
include/linux/vgaarb.h:66:9: warning: its scope is only this definition or declaration, which is probably not what you want
include/linux/vgaarb.h:99:34: warning: 'struct pci_dev' declared inside parameter list
include/linux/vgaarb.h:109:6: warning: 'struct pci_dev' declared inside parameter list
include/linux/vgaarb.h:121:8: warning: 'struct pci_dev' declared inside parameter list
include/linux/vgaarb.h:140:37: warning: 'struct pci_dev' declared inside parameter list

Signed-off-by: Randy Dunlap <rdunlap at xenotime.net>
Cc:	David Airlie <airlied at linux.ie>
Cc:	dri-devel at lists.freedesktop.org
---
 include/linux/vgaarb.h |    2 ++
 1 file changed, 2 insertions(+)

--- linux-next-20120130.orig/include/linux/vgaarb.h
+++ linux-next-20120130/include/linux/vgaarb.h
@@ -47,6 +47,8 @@
  */
 #define VGA_DEFAULT_DEVICE     (NULL)
 
+struct pci_dev;
+
 /* For use by clients */
 
 /**