Extend ieee488.c test coverage

Jan Breuer

2015-12-05 072c98d567c1e487c5471b4e52154da013fdd9f1

 libscpi/test/test_fifo.c

@@ -76,7 +76,7 @@
    CU_ASSERT_TRUE(fifo_remove(&fifo, &value));
    CU_ASSERT_EQUAL(value, 5);
    TEST_FIFO_COUNT(0);
    

    CU_ASSERT_FALSE(fifo_remove(&fifo, &value));
    TEST_FIFO_COUNT(0);
}