systemd: avoid musl specific patches affect glibc systems
systemd upstream only care about glibc. We made musl specific
patches so that systemd could work. But currently these patches
contain potential security issues.
So apply these patches only when the libc is musl.
Signed-off-by: Chen Qi <Qi.Chen@windriver.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org> Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Armin Kuster <akuster808@gmail.com>
