use filecoin-ffi@safer-ffi

[dignifiedquire]

ref filecoin-project/filecoin-ffi#247

[codecov]

Codecov Report

Merging #8538 (f6d1bf9) into master (f9a4a40) will increase coverage by 0.01%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #8538      +/-   ##
==========================================
+ Coverage   40.82%   40.84%   +0.01%     
==========================================
  Files         686      686              
  Lines       75697    75700       +3     
==========================================
+ Hits        30904    30916      +12     
+ Misses      39455    39440      -15     
- Partials     5338     5344       +6     

Impacted Files	Coverage Δ
storage/wdpost_sched.go	75.49% <0.00%> (-11.77%)	⬇️
chain/actors/builtin/miner/diff.go	48.52% <0.00%> (-10.30%)	⬇️
chain/exchange/peer_tracker.go	66.66% <0.00%> (-4.31%)	⬇️
chain/exchange/client.go	49.15% <0.00%> (-3.82%)	⬇️
chain/stmgr/call.go	65.94% <0.00%> (-3.25%)	⬇️
chain/events/events_height.go	68.90% <0.00%> (-2.53%)	⬇️
chain/gen/gen.go	68.19% <0.00%> (-1.23%)	⬇️
miner/miner.go	55.73% <0.00%> (-0.99%)	⬇️
storage/wdpost_changehandler.go	98.58% <0.00%> (-0.95%)	⬇️
extern/sector-storage/sched.go	85.93% <0.00%> (-0.77%)	⬇️
... and 15 more

[Stebalien]

Changes have already been merged to master.