Till now this value was parsed as raw integer using atol() and would
silently ignore any trailing suffix, causing unexpected behaviors when
set, e.g. to "512k". Let's make use of parse_size_err() on it so that
units are supported. This requires to turn it to uint as well, and
since it's sometimes compared to an int, we limit its range to
0..INT_MAX.
2f0c6ff3a5
