Fix ISO C warning.

tests/test-mishared.c

@@ -88,7 +88,7 @@ static void test_single(void)
 static struct ishared_s g_var = { 
     ISHARED_PTR_STATIC_INIT(ishared1, struct ishared_s),
     ISHARED_PTR_STATIC_INIT(ishared2, struct ishared_s),
-    {}
+    { 0 }
 };
 
 static void test_static(void)
@@ -109,7 +109,7 @@ static void test_static(void)
 #define MAX_THREAD 256
 #define MAX_VAR 5
 
-#define VAL(x) { ISHARED_PTR_STATIC_INIT(ishared1, struct ishared_s), ISHARED_PTR_STATIC_INIT(ishared2, struct ishared_s), {} } 
+#define VAL(x) { ISHARED_PTR_STATIC_INIT(ishared1, struct ishared_s), ISHARED_PTR_STATIC_INIT(ishared2, struct ishared_s), { 0 } }
 static struct ishared_s g_tab[MAX_VAR] = { 
     M_MAP_C(VAL, M_SEQ(1, MAX_VAR))
 };