Fix the length of the prime number list. Refs #2975

[SVN r52658]

test/unordered/Jamfile.v2

@@ -37,4 +37,5 @@ test-suite unordered
         [ run rehash_tests.cpp ]
         [ run equality_tests.cpp ]
         [ run swap_tests.cpp : : : <define>BOOST_UNORDERED_SWAP_METHOD=2 ]
+        [ run detail_tests.cpp ]
     ;