Improve removeFnsFromStack performance
Improve removeFnsFromStack performance

benchmark                         old ns/op     new ns/op     delta
BenchmarkRemoveFnsFromStack-8     1774          293           -83.48%

benchmark                         old allocs     new allocs     delta
BenchmarkRemoveFnsFromStack-8     3              1              -66.67%

benchmark                         old bytes     new bytes     delta
BenchmarkRemoveFnsFromStack-8     1632          704           -56.86%

Thomasdezeeuw/logger