Is equivalent to:
while (loopcount-- > 0);
That's obviously silly what for you want. Don't put a semicolon after a while loop condition unless you know what you're doing and why you need to do it. Put braces around the statements you want to be a part of the loop.
while(loopcount-- > 0)
The above makes even less sense, but I think you're trying to form a for loop. Either way, his loop should work.
while (loopcount > 0, loopcount--);
What I would rather do is use a for loop like this:
// loop body here....