Target reset happens when trying to do a ion_unmap_iommu on the above fd, which was never mapped. Added a check for non-zero virtual address. Change-Id: I9a4d81eea6ee0cdbe3e8bbcb0c1d05c005680555 CRs-Fixed: 394779 Signed-off-by: Srinu Gorle <sgorle@codeaurora.org> Signed-off-by: Neha Pandey <nehap@codeaurora.org>