detect-compiler: detect clang even if it found CUDA

detect-compiler: detect clang even if it found CUDA

In my setup, clang finds `/usr/local/cuda` and hence the output of
`clang -v` ends with this line:

	Found CUDA installation: /usr/local/cuda, version

This confuses the `detect-compiler` script because it matches _all_
lines that contain the needle "version" surrounded by spaces. As a
consequence, the `get_family` function returns two lines: "Ubuntu clang"
and above-mentioned line, which the `case` statement does not handle
well and hence reports "unknown compiler family" instead of the expected
set of "clang14", "clang13", ..., "clang1" output.

Let's unconfuse the script by letting it parse the first matching line
and ignore the rest.

Helped-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>
Acked-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Signed-off-by: Junio C Hamano <gitster@pobox.com>