configfs: configfs_create() init callback is never NULL and it never fails

... so make it return void and drop the check for it being non-NULL

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

diff --cc fs/configfs/configfs_internal.h
Simple merge

diff --cc fs/configfs/dir.c
Simple merge

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