cmd/upspin: add newlines to warning output
cmd/upspin: add newlines to warning output

Change-Id: I406a09a3028699231b26ba4253eba5aad6e2f7ea
Reviewed-on: https://upspin-review.googlesource.com/7643
Reviewed-by: Rob Pike <4dc7c9ec434ed06502767136789763ec11d2c4b7@google.com>

upspin/upspin,upspin/upspin