This avoids the following warning:
WARNING: .../meta/recipes-core/systemd/systemd_250.1.bb: Var
<do_install>:1: DeprecationWarning: invalid escape sequence \$
seen when doing `devtool finish --force-patch-refresh systemd meta`.
(From OE-Core rev: 427ca80eb4ea6c607b00028adcc9302e29db1368)
Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>