zeroize: fix unnecessary qualifications #631

Job	Run time
build (1.72.0, armv7a-none-eabi)	15s
cross (powerpc-unknown-linux-gnu, 1.72.0)	47s
build (1.72.0, thumbv7em-none-eabi)	19s
test (i686-unknown-linux-gnu, ubuntu-latest, 1.72.0, sudo apt update && sudo apt install gcc-mult...	30s
build (1.72.0, wasm32-unknown-unknown)	13s
test (i686-unknown-linux-gnu, ubuntu-latest, stable, sudo apt update && sudo apt install gcc-mult...	29s
build (stable, armv7a-none-eabi)	7s
test (x86_64-unknown-linux-gnu, ubuntu-latest, 1.72.0)	20s
build (stable, thumbv7em-none-eabi)	7s
build (stable, wasm32-unknown-unknown)	15s
test (x86_64-unknown-linux-gnu, ubuntu-latest, stable)	12s
test (x86_64-apple-darwin, macos-latest, 1.72.0)	24s
test (x86_64-apple-darwin, macos-latest, stable)	21s
aarch64 (aarch64-unknown-linux-gnu, 1.72.0)	41s
test (x86_64-pc-windows-msvc, windows-latest, 1.72.0)	50s
cross (powerpc-unknown-linux-gnu, stable)	32s
aarch64 (aarch64-unknown-linux-gnu, stable)	38s
test (x86_64-pc-windows-msvc, windows-latest, stable)	1m 47s
minimal-versions / minimal-versions	32s
	9m 19s

Provide feedback