Fix the error in sparse_img.py
Fix the error in sparse_img.py

Bug: 22046423
Change-Id: I0796e14df2b523570f0c485d146273f5e5aa5494
(cherry picked from commit 2b4ff174ff09d3d4f69897c8f8004c57836975b4)

xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build,xorware/android_build