Remove the dummy FS call from the Javascript tests

test/default/cmptest.h

@@ -137,9 +137,6 @@ int main(void)
     if (sodium_init() != 0) {
         return 99;
     }
-#ifdef __EMSCRIPTEN__
-    (void) fopen("/dev/null", "r");
-#endif
 
 #ifndef __EMSCRIPTEN__
     randombytes_set_implementation(&randombytes_salsa20_implementation);