ima: measure and appraise the IMA policy itself

Add support for measuring and appraising the IMA policy itself.

Changelog v4:
- use braces on both if/else branches, even if single line on one of the
branches - Dmitry
- Use the id mapping - Dmitry

Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: Petko Manolov <petkan@mip-labs.com>
Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
diff --git a/security/integrity/ima/ima_main.c b/security/integrity/ima/ima_main.c
index f764881..391f417 100644
--- a/security/integrity/ima/ima_main.c
+++ b/security/integrity/ima/ima_main.c
@@ -344,6 +344,7 @@
 	[READING_MODULE] = MODULE_CHECK,
 	[READING_KEXEC_IMAGE] = KEXEC_KERNEL_CHECK,
 	[READING_KEXEC_INITRAMFS] = KEXEC_INITRAMFS_CHECK,
+	[READING_POLICY] = POLICY_CHECK
 };
 
 /**