Fix reiserfs_file_release()

a) count file openers correctly; i_count use was completely wrong
b) use new mutex for exclusion between final close/open/truncate,
to protect tailpacking logics.  i_mutex use was wrong and resulted
in deadlocks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

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

diff --cc fs/reiserfs/inode.c
Simple merge

diff --cc fs/reiserfs/super.c
Simple merge

diff --cc include/linux/reiserfs_fs_i.h
Simple merge