map: fix flaky TestMapBatch/Hash

Hash table batch lookup proceeds by bucket, filling the user space
output buffer only if the entire bucket can fit. Depending on the
initial hash value chosen we may end up with a key to bucket
distribution leads to a lookup returning a count less than the full
size. For example:

    bucket keys
    0:     k1
    1:     k2, k3

In this case the first batch lookup with batch size 2 will return
count == 1, since only the 0th bucket fits entirely.

Account for this in the test case.

Signed-off-by: Lorenz Bauer <[email protected]>

map_test.go

@@ -149,8 +149,8 @@ func TestMapBatch(t *testing.T) {
 				}
 				qt.Assert(t, err, qt.IsNil)
 
-				qt.Assert(t, count, qt.Equals, len(lookupKeys))
-				for i, key := range lookupKeys {
+				qt.Assert(t, count <= len(lookupKeys), qt.IsTrue)
+				for i, key := range lookupKeys[:count] {
 					value := lookupValues[i]
 					qt.Assert(t, value, qt.Equals, contents[key], qt.Commentf("value for key %d should match", key))
 				}