IMA: handle comments in policy

IMA policy load parser will reject any policies with a comment.  This patch
will allow the parser to just ignore lines which start with a #.  This is not
very robust.  # can ONLY be used at the very beginning of a line.  Inline
comments are not allowed.

Signed-off-by: Eric Paris
Acked-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>