ceph: remove a few bogus declarations

There are three ceph page vector functions declared in
"fs/ceph/super.h" that don't belong there.  They're
probably left over from some long-ago code reorganization.

They're properly declared in "include/linux/ceph/libceph.h"
so just delete the ones in "super.h".

This and the next few commits resolve:
    http://tracker.ceph.com/issues/4053Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

fs/ceph/super.h

@@ -798,13 +798,7 @@ extern int ceph_mmap(struct file *file, struct vm_area_struct *vma);
 /* file.c */
 extern const struct file_operations ceph_file_fops;
 extern const struct address_space_operations ceph_aops;
-extern int ceph_copy_to_page_vector(struct page **pages,
-				    const char *data,
-				    loff_t off, size_t len);
-extern int ceph_copy_from_page_vector(struct page **pages,
-				    char *data,
-				    loff_t off, size_t len);
-extern struct page **ceph_alloc_page_vector(int num_pages, gfp_t flags);
+
 extern int ceph_open(struct inode *inode, struct file *file);
 extern int ceph_atomic_open(struct inode *dir, struct dentry *dentry,
 			    struct file *file, unsigned flags, umode_t mode,