eCryptfs: file->private_data is always valid
eCryptfs: file->private_data is always valid

When accessing the lower_file pointer located in private_data of
eCryptfs files, there is no need to check to see if the private_data
pointer has been initialized to a non-NULL value. The file->private_data
and file->private_data->lower_file pointers are always initialized to
non-NULL values in ecryptfs_open().

This change quiets a Smatch warning:

  CHECK   /var/scm/kernel/linux/fs/ecryptfs/file.c
fs/ecryptfs/file.c:321 ecryptfs_unlocked_ioctl() error: potential NULL dereference 'lower_file'.
fs/ecryptfs/file.c:335 ecryptfs_compat_ioctl() error: potential NULL dereference 'lower_file'.

Signed-off-by: Tyler Hicks <93eeee00a2beb1fbd6106ad8f59025f171ca91c6@canonical.com>
Reported-by: Dan Carpenter <ff341aa343d564f9e53e9dcb6996be8c04859a66@oracle.com>
Reviewed-by: Geyslan G. Bem <f4b1cbbbea5f92f5c62d2b429aae4742785e210f@gmail.com>
Cc: Al Viro <de609eb4d5d70b1d38ec6642adbfc33a2781f63c@zeniv.linux.org.uk>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs