turn recovery into a C++ binary

Change-Id: I68a67a4c8edec9a74463b3d4766005ce27b51316
diff --git a/minui/minui.h b/minui/minui.h
index 2e2f1f4..74da4e9 100644
--- a/minui/minui.h
+++ b/minui/minui.h
@@ -19,6 +19,10 @@
 
 #include <stdbool.h>
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 typedef void* gr_surface;
 typedef unsigned short gr_pixel;
 
@@ -69,4 +73,8 @@
 int res_create_surface(const char* name, gr_surface* pSurface);
 void res_free_surface(gr_surface surface);
 
+#ifdef __cplusplus
+}
+#endif
+
 #endif