Improve toolbox SIGPIPE behavior.

None of our tools -- except for top, which I'd fixed previously --
handles SIGPIE correctly. Let's just handle SIGPIPE in the driver.

Bug: https://code.google.com/p/android/issues/detail?id=157920
Change-Id: I322ea411f53c71585a64118c217d54389f675d4e
2 files changed