model: release_seq_head - rewrite RMW recursion as loop

model: release_seq_head - rewrite RMW recursion as loop

A bug in release sequences coce (independent of this patch) causes a huge
blowup of the recursion, yielding strange stack errors. So I address "@todo
Might it be better to make this into a loop", causing a loop of memory usage
instead. This can be triggered, for example, with:

  ./run.sh ./test/linuxrwlocks.o -e 1 -f 4 -m 1