Removing unused parameters in src/wal.cc
Removing unused parameters in src/wal.cc

This will address warnings during compilation.

Change-Id: Ibb4b9b0d6b3c27ddf06fa9cf0fe0a6d509d437e0

wurikiji/forestdb,couchbase/forestdb,hisundar/forestdb,couchbase/forestdb,wurikiji/forestdb,hisundar/forestdb