gpu: ion: Fix fragmentation debug message cond.

If an ion allocation fails because of memory fragmentation a debug
message should be printed. However, the logic that decides whether
the debug message should be printed or not is incorrect causing
the debug message to not be printed when the amount of space
available in the heap is equal to the requested size.

Change-Id: Iaaf8cd6742aeffab7bcb4806e485326fb9690945
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>