Strip newlines from PrintBuildbot{Link,StepText}.
Strip newlines from PrintBuildbot{Link,StepText}.

BUG=none
TEST=Pylint. Unit tests.

Change-Id: I36e57f467910186040385d0a68d9e88dd10fa047
Reviewed-on: https://gerrit.chromium.org/gerrit/28144
Tested-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Commit-Ready: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>

chadversary/chromiumos.chromite,coreos/chromite,coreos/chromite,zhang0137/chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,coreos/chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite