ima/policy: fix parsing of fsuuid

ima/policy: fix parsing of fsuuid

BugLink: http://bugs.launchpad.net/bugs/1747169
commit 36447456e1cca853188505f2a964dbbeacfc7a7a upstream.

The switch to uuid_t invereted the logic of verfication that &entry->fsuuid
is zero during parsing of "fsuuid=" rule. Instead of making sure the
&entry->fsuuid field is not attempted to be overwritten, we bail out for
perfectly correct rule.

Fixes: 787d8c530af7 ("ima/policy: switch to use uuid_t")
Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>