fix new rust lints (#1467) #1633

Job	Run time
ASAN	6m 30s
Bazel	5m 8s
Test Big Endian	9m 17s
macOS	1s
UBSAN	6m 28s
Ubuntu 18.04 (Build: Debug, Compilers: gcc-6/g++-6, Shared Library: true)	41s
Ubuntu 18.04 (Build: Debug, Compilers: clang-6.0/clang++-6.0, Shared Library: true)	43s
Windows 2019 (Generator: MinGW Makefiles, Shared Library: true)	19m 8s
Ubuntu 18.04 (Build: Debug, Compilers: clang-6.0/clang++-6.0, Shared Library: false)	45s
Windows 2019 (Generator: MinGW Makefiles, Shared Library: false)	19m 0s
Ubuntu 18.04 (Build: Release, Compilers: gcc-6/g++-6, Shared Library: true)	42s
Windows 2019 (Generator: Visual Studio 16 2019, Shared Library: true)	9m 2s
Ubuntu 18.04 (Build: Release, Compilers: gcc-6/g++-6, Shared Library: false)	14s
Windows 2019 (Generator: Visual Studio 16 2019, Shared Library: false)	9m 31s
Ubuntu 18.04 (Build: Release, Compilers: clang-6.0/clang++-6.0, Shared Library: true)	45s
Ubuntu 18.04 (Build: Release, Compilers: clang-6.0/clang++-6.0, Shared Library: false)	43s
	1h 28m 38s

Provide feedback