switch ->get_link() to delayed_call, kill ->put_link()

Documentation/filesystems/Locking

Documentation/filesystems/porting

Documentation/filesystems/vfs.txt

drivers/staging/lustre/lustre/llite/symlink.c

fs/9p/vfs_inode.c

fs/9p/vfs_inode_dotl.c

fs/affs/symlink.c

fs/autofs4/symlink.c

fs/btrfs/inode.c

fs/cifs/cifsfs.c

fs/cifs/cifsfs.h

fs/cifs/link.c

fs/coda/cnode.c

fs/configfs/symlink.c

fs/ecryptfs/inode.c

fs/ext2/symlink.c

fs/ext4/symlink.c

fs/f2fs/namei.c

fs/fuse/dir.c

fs/gfs2/inode.c