[PATCH] fuse: bump interface version

Change interface version to 7.4.

Following changes will need backward compatibility support, so store the minor
version returned by userspace.

Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>