msm: wfd: Free ion memory properly during a ion failure

This change takes care of freeing allocated ion memory
properly which avoids unnecessary memory leaks.

CRs-Fixed: 627325
Change-Id: Icbbb1f2c8f8b02541a38aedd0066c7b079b144fb
Signed-off-by: Deepak Verma <dverma@codeaurora.org>