KEYS: Move the flags representing required permission to linux/key.h

Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.

Whilst we're at it:

 (1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions
     with symbols in uapi/linux/input.h.

 (2) Don't use key_perm_t for a mask of required permissions, but rather limit
     it to the permissions mask attached to the key and arguments related
     directly to that.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
diff --git a/security/keys/internal.h b/security/keys/internal.h
index 80b2aac..5f20da0 100644
--- a/security/keys/internal.h
+++ b/security/keys/internal.h
@@ -176,20 +176,11 @@
 /*
  * Check to see whether permission is granted to use a key in the desired way.
  */
-static inline int key_permission(const key_ref_t key_ref, key_perm_t perm)
+static inline int key_permission(const key_ref_t key_ref, unsigned perm)
 {
 	return key_task_permission(key_ref, current_cred(), perm);
 }
 
-/* required permissions */
-#define	KEY_VIEW	0x01	/* require permission to view attributes */
-#define	KEY_READ	0x02	/* require permission to read content */
-#define	KEY_WRITE	0x04	/* require permission to update / modify */
-#define	KEY_SEARCH	0x08	/* require permission to search (keyring) or find (key) */
-#define	KEY_LINK	0x10	/* require permission to link */
-#define	KEY_SETATTR	0x20	/* require permission to change attributes */
-#define	KEY_ALL		0x3f	/* all the above permissions */
-
 /*
  * Authorisation record for request_key().
  */