This function accounted for ~1% of all allocs by tailscaled.
It is trivial to improve, so may as well.
name old time/op new time/op delta
KeyMarshalText-8 197ns ± 0% 47ns ± 0% -76.12% (p=0.016 n=4+5)
name old alloc/op new alloc/op delta
KeyMarshalText-8 200B ± 0% 80B ± 0% -60.00% (p=0.008 n=5+5)
name old allocs/op new allocs/op delta
KeyMarshalText-8 5.00 ± 0% 1.00 ± 0% -80.00% (p=0.008 n=5+5)
Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
ceb568202b