Don't use random number as pointers.

This is not legal (even if it works on all platforms). Also, this fixes
a warning.

test/src/misc/variables.c

@@ -154,13 +154,15 @@ static void test_strings( libvlc_int_t *p_libvlc )
 
 static void test_address( libvlc_int_t *p_libvlc )
 {
+    char dummy[i_var_count];
+
     int i;
     for( i = 0; i < i_var_count; i++ )
          var_Create( p_libvlc, psz_var_name[i], VLC_VAR_ADDRESS );
 
     for( i = 0; i < i_var_count; i++ )
     {
-        var_value[i].p_address = rand();
+        var_value[i].p_address = dummy + i;
         var_SetAddress( p_libvlc, psz_var_name[i], var_value[i].p_address );
     }