capabilities/syslog: open code cap_syslog logic to fix build failure

The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n.  This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.

The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller.  All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/security.c b/security/security.c
index 3ef5e2a..1b798d3 100644
--- a/security/security.c
+++ b/security/security.c
@@ -197,9 +197,9 @@
 	return security_ops->quota_on(dentry);
 }
 
-int security_syslog(int type, bool from_file)
+int security_syslog(int type)
 {
-	return security_ops->syslog(type, from_file);
+	return security_ops->syslog(type);
 }
 
 int security_settime(struct timespec *ts, struct timezone *tz)