audit: do not reject all AUDIT_INODE filter types

commit ab61d38e tried to merge the
invalid filter checking into a single function.  However AUDIT_INODE
filters were not verified in the new generic checker.  Thus such rules
were being denied even though they were perfectly valid.

Ex:
$ auditctl -a exit,always -F arch=b64 -S open -F key=/foo -F inode=6955 -F devmajor=9 -F devminor=1
Error sending add rule data request (Invalid argument)
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

kernel/auditfilter.c

@@ -343,6 +343,7 @@ static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 	case AUDIT_DEVMINOR:
 	case AUDIT_EXIT:
 	case AUDIT_SUCCESS:
+	case AUDIT_INODE:
 		/* bit ops are only useful on syscall args */
 		if (f->op == Audit_bitmask || f->op == Audit_bittest)
 			return -EINVAL;