[fpc-pascal] dos.pp GetLongName and GetShortName for mswindows

[Dale Welch]

file  rtl/win/dos.pp

typo / problem in function GetLongName and GetShortName 
it has 
   if ret = 0 then
it should be
  if ret <> 0 then
then it will work correctly. :-)

because the ret value is 0 if invalid file / directory passed.
ret is > then the passed bufferlen "255" if it needs a larger buffer to store it in
or it is between 1 and 255 if a valid value.

same error with GetShortName

reference
  http://windowssdk.msdn.microsoft.com/en-us/library/ms685896.aspx
  http://windowssdk.msdn.microsoft.com/en-us/library/ms685885.aspx

--- dale