ms: fix up template deduction failure

clang and gcc disagree, so just use a real var with the right type.

Change-Id: I590060d201445ad25cf5eb73c4b1360eaf6a6cea
diff --git a/Transceiver52M/ms/bladerf_specific.h b/Transceiver52M/ms/bladerf_specific.h
index f4abe57..9db8bf0 100644
--- a/Transceiver52M/ms/bladerf_specific.h
+++ b/Transceiver52M/ms/bladerf_specific.h
@@ -269,7 +269,8 @@
 
 		bool is_locked;
 		blade_check(bladerf_set_pll_enable, dev, true);
-		blade_check(bladerf_set_pll_refclk, dev, 10000000UL);
+		uint64_t refclock = 10000000UL;
+		blade_check(bladerf_set_pll_refclk, dev, refclock);
 		for (int i = 0; i < 20; i++) {
 			usleep(50 * 1000);
 			bladerf_get_pll_lock_state(dev, &is_locked);