atomisp: hmm: Remove the buffer object from the list before cleaning it

atomisp: hmm: Remove the buffer object from the list before cleaning it

BZ: 19462

Change-Id: I58b94cb7d824dfa154ae073e35ecbeeff1d78de9
Signed-off-by: Ilkka Koskinen <ilkka.koskinen@intel.com>
Reviewed-on: http://android.intel.com:8080/30888
Reviewed-by: Kruger, Jozef <jozef.kruger@intel.com>
Reviewed-by: Toivonen, Tuukka <tuukka.toivonen@intel.com>
Reviewed-by: Cohen, David A <david.a.cohen@intel.com>
Reviewed-by: Wang, Wen W <wen.w.wang@intel.com>
Reviewed-by: Gross, Mark <mark.gross@intel.com>
Tested-by: Lampila, KalleX <kallex.lampila@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>