Log: scheduler: add working set flag functions
... instead of set_bit()/clear_bit(), which improves trace messages like:
Bit 0x01000000 set by some_function:100 Bit 0x00800000 set by some_function:101
to:
Working set flags 0x01800000 (pe_flag_no_counts|pe_flag_no_compat) for some_tool set by some_function:100