dbginfo.sh: sort list of environment variables for readability

The "detour" with NUL terminated records ensures that sorting
works as expected for environment variables with values containing
one or more lines and thus '\n' as regular record separator.

Reviewed-by: Joern Siglen <siglen@de.ibm.com>
Signed-off-by: Steffen Maier <maier@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>

scripts/dbginfo.sh

@@ -427,7 +427,7 @@ CMDS="uname -a\
   :systemctl --all --no-pager list-unit-files\
   :systemd-delta\
   :ulimit -a\
-  :env\
+  :env --null | sort --zero-terminated | tr '\000' '\n'\
   :find /boot -print0 | sort -z | xargs -0 -n 10 ls -ld\
   :find /var/crash -print0 | sort -z | xargs -0 -n 10 ls -ld\
   :df -h\