qseecom: Fix ion memory issue during unload app failure

qseecom still need to free ion memory if unload app failed.
The previous xpu violation related to unload app failure is
actually due to race condition between send command, which
is fixed and now it is safe to free ion memory in error cases.

Change-Id: I7a09c753360eb015ece15c48ae1bb34e30479560
Signed-off-by: Zhen Kong <zkong@codeaurora.org>