fix sign of error to be positive when passed to strerror() am: 5c06efb178

Original change: https://android-review.googlesource.com/c/platform/frameworks/libs/net/+/2121994

Change-Id: Ie1267fb56440775a93a8f977e58dbc6fd14c9d55
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>