ocfs2: Add struct file to ocfs2_refcount_cow.

Add a new parameter 'struct file *' to ocfs2_refcount_cow
so that we can add readahead support later.

Signed-off-by: Tao Ma <tao.ma@oracle.com>

diff --cc fs/ocfs2/aops.c
Simple merge

diff --cc fs/ocfs2/file.c
Simple merge

diff --cc fs/ocfs2/refcounttree.c
Simple merge

diff --cc fs/ocfs2/refcounttree.h
Simple merge