src/utils_complain: Changed c_release() into a macro.

src/utils_complain: Changed c_release() into a macro.

While the c_complain*() functions are usually used in error conditions only,
c_release() is usually used whenever things went right (which should be the
more common case ;-)). In order to minimize the overhead in the latter case,
c_release() has been changed into a macro which checks if the complaint
actually has to be released and calls c_do_release() in that case. This
function then takes care of reporting the release-message (this is the
original implementation of c_release()). So, we remove the overhead of a
function call in the usual case, i.e. when we don't have to report any
messages.

Signed-off-by: Sebastian Harl <sh@tokkee.org>
Signed-off-by: Florian Forster <octo@huhu.verplant.org>