Fix a number of clang-tidy warnings

No functional changes. There are still plenty of atoi() warnings,
but most of those should go away as we convert all remaining
commands to binder.

Test: atest netd_integration_test netd_utils_test netd_integration_test
Change-Id: I15d6fd9523debf996dec9d0b3c3d7c11ae6444f3
5 files changed