apparmor: fix typos and spelling errors

Fix typos and spelling errors in apparmor module comments that were
identified using the codespell tool.
No functional changes - documentation only.

Signed-off-by: Tanya Agarwal <tanyaagarwal25699@gmail.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Ryan Lee <ryan.lee@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>