The mmap2() on a directory was successful, resulting in a SIGBUS
signal later. This patch removes mmap() from the list of possible
ecryptfs_dir_fops so that mmap() isn't possible on eCryptfs directory
files.
https://bugs.launchpad.net/ecryptfs/+bug/400443
Reported-by: Adrian C. <anrxc@sysphere.org> Signed-off-by: Tyler Hicks <tyhicks@linux.vnet.ibm.com>