[PATCH] eCryptfs: export user key type

Export this symbol to GPL modules for eCryptfs: an out-of-tree GPL'ed
filesystem.

Signed off by: Michael Halcrow <mhalcrow@us.ibm.com>

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>