gpu: ion: Fix fragmentation message log condition

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 it should.

Change-Id: I6537171db0a47ba072d182e9bb3125cac5513ff9
Signed-off-by: Olav Haugan <ohaugan@codeaurora.org>