Fix the usage message for crc32_bench #1110

Job	Run time
Build and test (stable, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 3s
QEMU build & test (stable, ubuntu-latest, s390x-unknown-linux-gnu, s390x-linux-gnu-gcc)	1m 0s
Clippy	23s
cargo-c dynamic library	16s
Build and test (msrv, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 4s
QEMU build & test (stable, ubuntu-latest, i686-unknown-linux-gnu, i686-linux-gnu-gcc)	37s
Clippy (--no-default-features --features="c-allocator")	14s
Build and test (beta, ubuntu-latest, x86_64-unknown-linux-gnu)	1m 32s
Clippy (--no-default-features --features="rust-allocator")	27s
Build and test (stable, macos-latest, x86_64-apple-darwin)	1m 5s
Smoke-test fuzzing targets (default)	2m 31s
Smoke-test fuzzing targets (c-allocator)	2m 40s
Build and test (stable, macos-14, aarch64-apple-darwin)	56s
Smoke-test fuzzing targets (stable, macos-14, aarch64-apple-darwin)	2m 41s
Build and test (stable-x86_64-gnu, windows-2022, x86_64-pc-windows-gnu)	2m 16s
Smoke-test fuzzing targets (rust-allocator)	2m 39s
vanilla dynamic library	41s
Miri	1m 59s
wasm32	48s
run flate2 test suite	19s
	25m 11s

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