busybox: Set PATH in syslog initscript

busybox: Set PATH in syslog initscript

This script is not always called with /sbin and /usr/sbin in the PATH
already, for example when called via ssh. Explicitly set PATH to make
sure it includes /sbin and /usr/sbin since that's where start-stop-daemon
is located.

Signed-off-by: Martijn de Gouw <martijn.de.gouw@prodrive-technologies.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>