[gnome-battery-bench] Explicitly initialize a variable make gcc happy

[Christian Kellner <gicmo src gnome org>]

commit c01ac22b60b379956ca2f00b59dd85d7c76b1b66
Author: Christian Kellner <gicmo gnome org>
Date:   Tue Mar 14 14:08:27 2017 +0100

    Explicitly initialize a variable make gcc happy

 src/system-info.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/src/system-info.c b/src/system-info.c
index 8301ee4..ed99c6e 100644
--- a/src/system-info.c
+++ b/src/system-info.c
@@ -455,7 +455,7 @@ read_mem_info(void)
 static char *
 get_renderer_info (void)
 {
-    g_autoptr(GDBusProxy) proxy;
+    g_autoptr(GDBusProxy) proxy = NULL;
     g_autoptr(GVariant) var = NULL;
     g_autoptr(GError) error = NULL;
     const char *renderer = "Unknown";