ANDROID: fscrypt: remove unnecessary fscrypto.h

This patch removes fscrypto.h which was missed to remove when porting the
latest fs/crypto stuffs.

Change-Id: Ib17cba17d48535b0d754ae52537053098248a036
Fixes: 13f00235 ("f2fs: catch up to v4.14-rc1")
Signed-off-by: Jaegeuk Kim <jaegeuk@google.com>