cpufreq: interactive: fix crash on error paths in get_tokenized_data

Use separate variable for error code, free proper pointer.

Reported-by: Arve Hjønnevåg <arve@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Pranav Vashi <neobuddy89@gmail.com>