modemmanager: Fix build with gcc9

Signed-off-by: Khem Raj <raj.khem@gmail.com>

meta-oe/recipes-connectivity/modemmanager/modemmanager/0001-Do-not-pass-null-string-to-s-printf-formatted-string.patch

@@ -0,0 +1,31 @@
+From b8862e6af1c6d022b8c182098e7deddb874ece19 Mon Sep 17 00:00:00 2001
+From: Khem Raj <raj.khem@gmail.com>
+Date: Tue, 18 Dec 2018 23:10:44 -0800
+Subject: [PATCH] Do not pass null string to %s printf formatted string
+
+Here the string is already decided to be NULL and passing
+a null pointer to %s will not work
+
+Fixes
+error: '%s' directive argument is null
+
+Upstream-Status: Submitted [https://gitlab.freedesktop.org/mobile-broadband/ModemManager/merge_requests/67]
+
+Signed-off-by: Khem Raj <raj.khem@gmail.com>
+---
+ plugins/mtk/mm-broadband-modem-mtk.c | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/plugins/mtk/mm-broadband-modem-mtk.c b/plugins/mtk/mm-broadband-modem-mtk.c
+index 475a63ac..541de4a5 100644
+--- a/plugins/mtk/mm-broadband-modem-mtk.c
++++ b/plugins/mtk/mm-broadband-modem-mtk.c
+@@ -191,7 +191,7 @@ get_supported_modes_ready (MMBaseModem *self,
+ 
+     response = mm_base_modem_at_command_finish (MM_BASE_MODEM (self), res, &error);
+     if (!response) {
+-        mm_dbg ("Fail to get response %s", response);
++        mm_dbg ("Fail to get response");
+         g_task_return_error (task, error);
+         g_object_unref (task);
+         return;

meta-oe/recipes-connectivity/modemmanager/modemmanager_1.8.2.bb

@@ -13,6 +13,7 @@ DEPENDS = "glib-2.0 libgudev dbus-glib intltool-native"
 
 SRC_URI = "http://www.freedesktop.org/software/ModemManager/ModemManager-${PV}.tar.xz \
            file://0001-Do-not-set-Wno-unused-but-set-variable.patch \
+           file://0001-Do-not-pass-null-string-to-s-printf-formatted-string.patch \
            "
 
 SRC_URI[md5sum] = "a49c9f73e46c7b89e5efedda250d22c0"