bus-bloom: Fix bloom filter calculation

bus-bloom: Fix bloom filter calculation

i is being used incorrectly.  It is used to refer to the number of
indexes calculated so far (out of k).  However, it is also incremented
when a new hash key is being used.  This means that the results are
inconsistent with the desired behavior described in PORTING-DBUS1
document.

The expected result is that for the default values of m and k (512, 8)
the 1st hash key should produce 4 indexes.  The second hash key is used
for the next 4 and overall 8 indexes into m are calculated.

The current behavior results in 6 indexes being calculated, 4 coming
from hash key 1 and 2 others from hash key 5.