202606211212

fix: cppcheck warnings

cpulimit_test.c:5902:37: style: The scope of the variable
'nread' can be reduced. [variableScope]
    ssize_t nwritten, expected_len, nread;
                                    ^
cpulimit_test.c:5910:11: style: Variable 'accessible_msg'
can be declared as pointer to const [constVariablePointer]
    char *accessible_msg;
          ^
cpulimit_test.c:5911:11: style: Variable 'not_found_msg'
can be declared as pointer to const [constVariablePointer]
    char *not_found_msg;
          ^