test_sysctl: add simple proc_douintvec() case

Test against a simple proc_douintvec() case. While at it, add
a test against UINT_MAX. Make sure UINT_MAX works, and UINT_MAX+1
will fail and that negative values are not accepted.

Cc: Kees Cook <keescook@chromium.org>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Shuah Khan <shuah@kernel.org>
Signed-off-by: Luis R. Rodriguez <mcgrof@kernel.org>
2 files changed