- exec_t belongs to service.h, the main place where it is used/needed
- code for executing exec_t is moved to runsvc for the same reason
- what is left are NORETURN and ARRAY_SIZE
- the former can be replaced with direct attribute usage since
the only relevant compilers all support the attribute.
- the later is only used in 3 places and can be trivially replaced
with direct usage of sizeof().
Signed-off-by: David Oberhollenzer <goliath@infraroot.at>