select/cons_res - fix debug flag SelectType handling in select_p_job_test.

Previous logic initialized a static variable once and forever. This
variable was used as a test to call or not log_job_resources and
dynamic changes through 'scontrol setdebugflags [+|-]SelectType' would
have no effect. New logic uses the standard select_debug_flags as
everywhere else and aligns with cons_tres logic.

Bug 7137.