Initialize array to mute cppcheck

[ysyrota]

Muted cppcheck on false positive

Description

This fix is intended to mute the following cppcheck warning:

test-duoapi.c:43:22: warning: Uninitialized variable: params [uninitvar]
                if ((params[i].key = strsep(&p, "=")) == NULL)
                     ^
test-duoapi.c:80:[5](https://github.com/duosecurity/libduo/actions/runs/14867606827/job/41748192934#step:5:6)8: note: Calling function '_parse_line', 4th argument 'params' value is <Uninit>
                if ((n = _parse_line(buf, &method, &uri, params,
                                                         ^
test-duoapi.c:3[8](https://github.com/duosecurity/libduo/actions/runs/14867606827/job/41748192934#step:5:9):49: note: Assuming condition is false
        if ((*method = strsep(&p, " ")) == NULL ||
                                                ^
test-duoapi.c:43:22: note: Uninitialized variable: params
                if ((params[i].key = strsep(&p, "=")) == NULL)

How Has This Been Tested?

CI

Types of Changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)