Used Error while updating bench - #5 by rmehta and resolve the problem.
Put the return in the patch file and ran the bench update --patch
Faced next problem in /home/frappe/frappe-bench/apps/erpnext/erpnext/patches/v4_0/validate_v3_patch.py and followed same procedure to bypass the patch as it was not applicable.
And erpnext.patches.v4_0.move_warehouse_user_to_restrictions indicating pymysql.err.ProgrammingError: (1146, u"Table ‘4415908876ee97c3.tabWarehouse User’ doesn’t exist"). Bypassed it as well.
This happened to many more patches.