Fix WORD_BIT test.

The only explanation for this and the unistd_test failures is that I
wasn't actually running the code I thought I was. There are some unrelated
netdb_test failures still to come...

Bug: N/A
Test: ran tests
Change-Id: I91af9d2d6a42f5433fa27e7cd8f5b903e1af36ba
diff --git a/tests/limits_test.cpp b/tests/limits_test.cpp
index ed42dbb..e5902ad 100644
--- a/tests/limits_test.cpp
+++ b/tests/limits_test.cpp
@@ -20,7 +20,7 @@
 
 TEST(limits, macros) {
   ASSERT_EQ(8, CHAR_BIT);
-  ASSERT_EQ(static_cast<int>(sizeof(int)), WORD_BIT);
+  ASSERT_EQ(8 * static_cast<int>(sizeof(int)), WORD_BIT);
   ASSERT_EQ(20, NZERO);
 #if !defined(MB_LEN_MAX)
 #error MB_LEN_MAX