build: missing newline when printing build details on error

[crazy-max]

Before

foo@bar:~ $ docker buildx build .
...
------
Dockerfile:356
--------------------
 355 |     ARG TARGETPLATFORM
 356 | >>> RUN --mount=type=cache,sharing=locked,id=moby-rootlesskit-aptlib,target=/var/lib/apt \
 357 | >>>     --mount=type=cache,sharing=locked,id=moby-rootlesskit-aptcache,target=/var/cache/apt \
 358 | >>>         apt-get update && xx-apt-get install -y --no-install-recommends \
 359 | >>>             gcc libc6-dev
 360 |     ENV GO111MODULE=on
--------------------
ERROR: failed to solve: process "/bin/sh -c apt-get update && xx-apt-get install -y --no-install-recommends             gcc libc6-dev" did not complete successfully: exit code: 100

View build details: docker-desktop://dashboard/build/default/default/oj5lusuq2n0ufovvphbaxfjn0foo@bar:~ $

After

foo@bar:~ $ docker buildx build .
...
------
Dockerfile:356
--------------------
 355 |     ARG TARGETPLATFORM
 356 | >>> RUN --mount=type=cache,sharing=locked,id=moby-rootlesskit-aptlib,target=/var/lib/apt \
 357 | >>>     --mount=type=cache,sharing=locked,id=moby-rootlesskit-aptcache,target=/var/cache/apt \
 358 | >>>         apt-get update && xx-apt-get install -y --no-install-recommends \
 359 | >>>             gcc libc6-dev
 360 |     ENV GO111MODULE=on
--------------------
ERROR: failed to solve: process "/bin/sh -c apt-get update && xx-apt-get install -y --no-install-recommends             gcc libc6-dev" did not complete successfully: exit code: 100

View build details: docker-desktop://dashboard/build/default/default/oj5lusuq2n0ufovvphbaxfjn0
foo@bar:~ $

[jedevc]

No need to release-note this, since the original feature wasn't under the release notes.