eCryptfs: Collapse crypt_page_offset() into crypt_extent()

crypt_page_offset() simply initialized the two scatterlists and called
crypt_scatterlist() so it is simple enough to move into the only
function that calls it.

Signed-off-by: Tyler Hicks <tyhicks@canonical.com>

diff --cc fs/ecryptfs/crypto.c
Simple merge