MINOR: http: Regroup return statements of http_res_get_intercept_rule at the end

MINOR: http: Regroup return statements of http_res_get_intercept_rule at the end

Instead of having multiple return statements spreaded here and there in middle
of the function, we just exit from the loop setting the right return code. It
let a chance to do some work before leaving the function. It is also less error
prone.