ecryptfs: debug: Demote a couple of kernel-doc abuses

Fixes the following W=1 kernel build warning(s):

 fs/ecryptfs/debug.c:13: warning: Incorrect use of kernel-doc format:  * ecryptfs_dump_auth_tok - debug function to print auth toks
 fs/ecryptfs/debug.c:19: warning: Function parameter or member 'auth_tok' not described in 'ecryptfs_dump_auth_tok'
 fs/ecryptfs/debug.c:19: warning: expecting prototype for eCryptfs(). Prototype was for ecryptfs_dump_auth_tok() instead

Cc: Tyler Hicks <code@tyhicks.com>
Cc: "Michael A. Halcrow" <mahalcro@us.ibm.com>
Cc: ecryptfs@vger.kernel.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Tyler Hicks <code@tyhicks.com>