ecryptfs: fix a memory leak bug in ecryptfs_init_messaging()

ecryptfs: fix a memory leak bug in ecryptfs_init_messaging()

In ecryptfs_init_messaging(), if the allocation for 'ecryptfs_msg_ctx_arr'
fails, the previously allocated 'ecryptfs_daemon_hash' is not deallocated,
leading to a memory leak bug. To fix this issue, free
'ecryptfs_daemon_hash' before returning the error.

Cc: stable@vger.kernel.org
Fixes: 88b4a07e6610 ("[PATCH] eCryptfs: Public key transport mechanism")
Signed-off-by: Wenwen Wang <wenwen@cs.uga.edu>
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>