Separate out common fstatat code into vfs_fstatat

This is a version incorporating Christoph's suggestion.

Separate out common *fstatat functionality into a single function
instead of duplicating it all over the code.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/fs.h b/include/linux/fs.h
index e766be0..257f4d3 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -2302,6 +2302,7 @@
 extern int vfs_stat_fd(int dfd, char __user *, struct kstat *);
 extern int vfs_lstat_fd(int dfd, char __user *, struct kstat *);
 extern int vfs_fstat(unsigned int, struct kstat *);
+extern int vfs_fstatat(int , char __user *, struct kstat *, int);
 
 extern int do_vfs_ioctl(struct file *filp, unsigned int fd, unsigned int cmd,
 		    unsigned long arg);