kernel: mm/writeback: fix possible divide-by-zero in wb_dirty_limits(), again

REJECTED CVE...

PT-2024-7325

Name of the Vulnerable Software and Affected Versions: Linux kernel affected versions not specified Description: The issue is related to a possible divide-by-zero error in the wb dirty limits function. This error occurs because the thresh value, which is an unsigned long, is passed as a u32 divis...