allocator: minor fix for deallocOsPages
allocator: minor fix for deallocOsPages

dom96/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,russpowers/Nim,russpowers/Nim,dom96/Nim,russpowers/Nim,dom96/Nim