Log Message:
fix function prototype to match body in order to avoid:

>xfce-taskmanager-linux.c:33:6: error: conflicting types for 'get_task_details'
> void get_task_details(pid_t pid,struct task *task)
>      ^
>In file included from xfce-taskmanager-linux.c:30:0:
>xfce-taskmanager-linux.h:41:6: note: previous declaration of \ 
'get_task_details' was here
> void get_task_details(gint pid,struct task *task);
>      ^