Refactor cl_spec tests variable names
Refactor cl_spec tests variable names

Rename `exitcode` to `errcnt` since the variable is not really an exit
code, but rather an error count. There are only a few places where the
exit code is actually used, so in these places keep the `exitcode`
variable name.

Olivine-Labs/busted,istr/busted,o-lim/busted