video: tegra: host: fix Coverity issues

video: tegra: host: fix Coverity issues

- fix dereference of NULL return value. Add a NULL check
  Coverity id : 23335
- fix logically dead code
  handle function return values and use them for error checking
  Coverity id : 23733
- fix write to pointer after free
  free the pointer only after all operations are performed on it
  Coverity id : 23719
- fix dereference before NULL check
  check for NULL before dereferencing the variable
  Coverity id : 22918
- fix out of bounds read
  first check if value of variable 'i' is within range and
  then only use it as array index
  Coverity id : 23662

Bug 1329327

Change-Id: I70c9d6b00672211c7aaecc023ff2229efb52517f
Signed-off-by: Deepak Nibade <dnibade@nvidia.com>
Reviewed-on: http://git-master/r/256283
Reviewed-by: Mandar Padmawar <mpadmawar@nvidia.com>
Tested-by: Mandar Padmawar <mpadmawar@nvidia.com>