Removed extra 'pulling file' message.

Taking a zip bugreport has 2 phases: generating the bugreport and
pulling the file.

Initially adb was printing 2 messages, but since the latter is almost
instantaneously, it could be confusing to have 2 lines...

Fixes: 30451250
Change-Id: I1c6cc6163492c1fb6064667dfdb7aaf6ed4c4c6f
(cherry picked from commit f7c38b4c)