[PATCH] relayfs: export relayfs_create_file() with fileops param

This patch adds a mandatory fileops param to relayfs_create_file() and exports
that function so that clients can use it to create files defined by their own
set of file operations, in relayfs.  The purpose is to allow relayfs
applications to create their own set of 'control' files alongside their relay
files in relayfs rather than having to create them in /proc or debugfs for
instance.  relayfs_create_file() is also used by relay_open_buf() to create
the relay files for a channel.  In this case, a pointer to
relayfs_file_operations is passed in, along with a pointer to the buffer
associated with the file.

Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>