haiku: Fix unit tests, reduce warnings #996

Job	Run time
Rustfmt	13s
Test (stable)	20s
Check (armv7-sony-vita-newlibeabihf)	35s
Test (1.63.0)	4m 2s
Clippy	14s
Check (i686-unknown-hurd-gnu)	29s
Check (aarch64-apple-ios)	15s
Check (aarch64-linux-android)	14s
Docs (armv7-sony-vita-newlibeabihf)	27s
Test (beta)	20s
Docs (i686-unknown-hurd-gnu)	28s
Docs (aarch64-apple-ios)	13s
Check (x86_64-apple-darwin)	16s
Test (nightly)	21s
Docs (aarch64-linux-android)	15s
Check (x86_64-unknown-fuchsia)	13s
Test (macos)	45s
Docs (x86_64-apple-darwin)	15s
Check (x86_64-pc-windows-msvc)	14s
Test (windows)	1m 3s
Docs (x86_64-unknown-fuchsia)	12s
Check (x86_64-pc-solaris)	18s
Docs (x86_64-pc-windows-msvc)	14s
Check (x86_64-unknown-freebsd)	15s
Docs (x86_64-pc-solaris)	13s
Check (x86_64-unknown-illumos)	14s
Docs (x86_64-unknown-freebsd)	14s
Check (x86_64-unknown-linux-gnu)	15s
Docs (x86_64-unknown-illumos)	12s
Check (x86_64-unknown-linux-musl)	18s
Docs (x86_64-unknown-linux-gnu)	13s
Check (x86_64-unknown-netbsd)	17s
Docs (x86_64-unknown-linux-musl)	13s
Check (x86_64-unknown-redox)	13s
Docs (x86_64-unknown-netbsd)	14s
Check (armv7-linux-androideabi)	14s
Docs (x86_64-unknown-redox)	14s
Check (i686-linux-android)	15s
Docs (armv7-linux-androideabi)	15s
Docs (i686-linux-android)	13s
	15m 58s

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