Fix fpgetcwd for openbsd

git-svn-id: trunk@19410 -

rtl/bsd/ossysc.inc

@@ -534,8 +534,15 @@ begin
                End;
            End
       end
-         else
-            pt:=nil;
+{$ifdef openbsd}
+   { At least for openbsd, a positive return value is
+     the length of the returned pchar }
+   else if (ret<0) then
+{$endif openbsd}
+     begin
+       seterrno(-ret);
+       pt:=nil;
+     end;
  Fpgetcwd:=pt;
 end;