#539 DOXBOX returning wrong DOS error code

[fred469]

Attempting to delete a disk file (Int 21h AH=41h) that was set to R/O status, returns DOS error code 2 ('File not found'). It should be code 5 ('Permission denied').

[fred469]

Same for INT21h AH=3C (Create file) on existing R/O file i.e. returns code 2 instead of 5.