Fix docs on gen_event optional callback
Fix docs on gen_event optional callback

It returns `ok`, instead of `noreply`.
dumbbell/otp,bsmr-erlang/otp,aboroska/otp,g-andrade/otp,jj1bdx/otp,RoadRunnr/otp,getong/otp,bsmr-erlang/otp,uabboli/otp,potatosalad/otp,vladdu/otp,electricimp/otp,emacsmirror/erlang,vinoski/otp,bsmr-erlang/otp,dumbbell/otp,erlang/otp,lrascao/otp,bsmr-erlang/otp,lrascao/otp,erlang/otp,jj1bdx/otp,jj1bdx/otp,ferd/otp,potatosalad/otp,rlipscombe/otp,vladdu/otp,potatosalad/otp,getong/otp,jj1bdx/otp,erlang/otp,potatosalad/otp,aboroska/otp,bjorng/otp,legoscia/otp,mikpe/otp,erlang/otp,getong/otp,legoscia/otp,vinoski/otp,mikpe/otp,erlang/otp,rlipscombe/otp,g-andrade/otp,ferd/otp,isvilen/otp,kvakvs/otp,lrascao/otp,bjorng/otp,emacsmirror/erlang,emacsmirror/erlang,kvakvs/otp,uabboli/otp,vladdu/otp,bsmr-erlang/otp,potatosalad/otp,ferd/otp,vladdu/otp,RoadRunnr/otp,uabboli/otp,legoscia/otp,isvilen/otp,rlipscombe/otp,rlipscombe/otp,g-andrade/otp,bjorng/otp,mikpe/otp,rlipscombe/otp,isvilen/otp,vinoski/otp,vladdu/otp,dumbbell/otp,erlang/otp,isvilen/otp,ferd/otp,bsmr-erlang/otp,aboroska/otp,emacsmirror/erlang,dgud/otp,g-andrade/otp,lrascao/otp,getong/otp,dumbbell/otp,aboroska/otp,getong/otp,vinoski/otp,legoscia/otp,erlang/otp,dumbbell/otp,getong/otp,g-andrade/otp,ferd/otp,dgud/otp,vinoski/otp,emacsmirror/erlang,ferd/otp,legoscia/otp,g-andrade/otp,emacsmirror/erlang,g-andrade/otp,RoadRunnr/otp,uabboli/otp,potatosalad/otp,electricimp/otp,dgud/otp,legoscia/otp,aboroska/otp,RoadRunnr/otp,aboroska/otp,g-andrade/otp,dumbbell/otp,aboroska/otp,ferd/otp,isvilen/otp,dgud/otp,vladdu/otp,lrascao/otp,getong/otp,RoadRunnr/otp,RoadRunnr/otp,potatosalad/otp,electricimp/otp,vladdu/otp,dgud/otp,bsmr-erlang/otp,uabboli/otp,getong/otp,kvakvs/otp,electricimp/otp,dgud/otp,legoscia/otp,getong/otp,rlipscombe/otp,rlipscombe/otp,lrascao/otp,vinoski/otp,vinoski/otp,erlang/otp,isvilen/otp,bjorng/otp,mikpe/otp,kvakvs/otp,electricimp/otp,kvakvs/otp,ferd/otp,RoadRunnr/otp,lrascao/otp,bsmr-erlang/otp,vinoski/otp,isvilen/otp,jj1bdx/otp,g-andrade/otp,jj1bdx/otp,bjorng/otp,rlipscombe/otp,emacsmirror/erlang,dgud/otp,mikpe/otp,aboroska/otp,electricimp/otp,mikpe/otp,mikpe/otp,dumbbell/otp,bjorng/otp,rlipscombe/otp,dgud/otp,legoscia/otp,emacsmirror/erlang,emacsmirror/erlang,dgud/otp,dumbbell/otp,electricimp/otp,jj1bdx/otp,bjorng/otp,isvilen/otp,mikpe/otp,bsmr-erlang/otp,jj1bdx/otp,vinoski/otp,ferd/otp,vladdu/otp,lrascao/otp,isvilen/otp,kvakvs/otp,electricimp/otp,bjorng/otp,uabboli/otp,uabboli/otp,legoscia/otp,dumbbell/otp,aboroska/otp,lrascao/otp,potatosalad/otp,dumbbell/otp,potatosalad/otp,mikpe/otp,vladdu/otp,RoadRunnr/otp,bjorng/otp,emacsmirror/erlang,vinoski/otp,g-andrade/otp,dgud/otp,bjorng/otp,RoadRunnr/otp,potatosalad/otp,mikpe/otp,kvakvs/otp,kvakvs/otp,jj1bdx/otp,erlang/otp,getong/otp,uabboli/otp,jj1bdx/otp,rlipscombe/otp,electricimp/otp,uabboli/otp,kvakvs/otp,erlang/otp,isvilen/otp