security: add cred argument to security_capable()

Expand security_capable() to include cred, so that it can be usable in a
wider range of call sites.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
diff --git a/kernel/capability.c b/kernel/capability.c
index 2f05303..9e9385f 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -306,7 +306,7 @@
 		BUG();
 	}
 
-	if (security_capable(cap) == 0) {
+	if (security_capable(current_cred(), cap) == 0) {
 		current->flags |= PF_SUPERPRIV;
 		return 1;
 	}