polyval: fix typo in `karatsuba1` comment (#222) #399

Job	Run time
armv8 (aarch64-unknown-linux-gnu, nightly)	1m 12s
build (1.81.0, thumbv7em-none-eabi)	15s
clmul (i686-unknown-linux-gnu, 1.81.0, sudo apt update && sudo apt install gcc-multilib)	39s
build (1.81.0, wasm32-unknown-unknown)	21s
autodetect (i686-unknown-linux-gnu, 1.81.0, sudo apt update && sudo apt install gcc-multilib)	44s
clmul (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	31s
cross (aarch64-unknown-linux-gnu)	1m 4s
build (stable, thumbv7em-none-eabi)	7s
clmul (x86_64-unknown-linux-gnu, 1.81.0)	19s
autodetect (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	35s
cross (powerpc-unknown-linux-gnu)	1m 4s
build (stable, wasm32-unknown-unknown)	8s
clmul (x86_64-unknown-linux-gnu, stable)	16s
autodetect (x86_64-unknown-linux-gnu, 1.81.0)	19s
autodetect (x86_64-unknown-linux-gnu, stable)	27s
soft (i686-unknown-linux-gnu, 1.81.0, sudo apt update && sudo apt install gcc-multilib)	2m 9s
soft (i686-unknown-linux-gnu, stable, sudo apt update && sudo apt install gcc-multilib)	2m 23s
soft (x86_64-unknown-linux-gnu, 1.81.0)	16s
soft (x86_64-unknown-linux-gnu, stable)	12s
	13m 1s

Provide feedback