init: Set and export PATH before running any external commands

busybox sh and klibc dash have different default values for $PATH
which could affect which could affect which commands we run later.

klibc dash also does not export $PATH, and this means we fail to
run fsck - it is executed indirectly through logsave, and logsave
cannot find it.

Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

init

@@ -2,6 +2,10 @@
 
 echo "Loading, please wait..."
 
+# Default PATH differs between shells, and is not automatically exported
+# by klibc dash.  Make it consistent.
+export PATH=/sbin:/usr/sbin:/bin:/usr/bin
+
 [ -d /dev ] || mkdir -m 0755 /dev
 [ -d /root ] || mkdir -m 0700 /root
 [ -d /sys ] || mkdir /sys