msm: mdss: fix the ION memory leak on 8x10

The memory flag is not initialized properly during ION map.
Also, the memory is not free due to the incorrect validation
at free time.

Change-Id: I172cb0f68f4cdc131b70478e6c0123136075326d
Signed-off-by: Xiaoming Zhou <zhoux@codeaurora.org>