Bluetooth: Use %llu for printing duration details of selftests

The duration variable for the selftests is unsigned long long and with
that use %llu instead of %lld when printing the results.

Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Johan Hedberg <johan.hedberg@intel.com>
diff --git a/net/bluetooth/selftest.c b/net/bluetooth/selftest.c
index 9c67315..378f406 100644
--- a/net/bluetooth/selftest.c
+++ b/net/bluetooth/selftest.c
@@ -184,7 +184,7 @@
 	delta = ktime_sub(rettime, calltime);
 	duration = (unsigned long long) ktime_to_ns(delta) >> 10;
 
-	BT_INFO("ECDH test passed in %lld usecs", duration);
+	BT_INFO("ECDH test passed in %llu usecs", duration);
 
 	return 0;
 }