Thread: passing argument 1 of 'strlen' makes pointer from integer without a cast

I write code witch generate file name based on: destination directory settings, radio station presets list and current time.

If users store radio station name (app presets) with white space in name:

Europa FM
Paprika Radio
Radio France Internationale
...........................
Rock FM

I want to remove whitespace for recording radio station filename and result look like this:

/home/ubuntu/Desktop/EuropaFM_07042012-111705.ogg

Code:

static int start_recording(const gchar *destination, const char* station, const char* time)
{
    Recording* recording;
    char *filename;

    char* remove_whitespace(station)
    {
        char* result = malloc(strlen(station)+1);
        char* i;
        int temp = 0;
        for( i = station; *i; ++i)
            if(*i != ' ')
            {
                result[temp] = (*i);
                ++temp;
            }
        result[temp] = '\0';
        return result;
    }

    filename = g_strdup_printf(_("%s/%s_%s"), 
        destination, 
        remove_whitespace(station),
        time);
    recording = recording_start(filename);
    g_free(filename);
    if (!recording)
        return -1;

    recording->station = g_strdup(station);
    tray_icon_items_set_sensible(FALSE);

    record_status_window(recording);

    run_status_window(recording);

    return 1;
}

But this get warnings:

warning: passing argument 1 of 'strlen' makes pointer from integer without a cast [enabled by default] warning: assignment makes pointer from integer without a cast [enabled by default]

I appreciate your help. Thanks.