Remove Little Snitch via script
There are multiple problems with that script:


Bare string variables with embedded whitespace: put "" around
the killall arguments. 
Overkill: if you're going to remove the software and reboot, there's
no need to whack processes. There's a risk with LS that you could
shoot your own session (and script) if taking out the LS processes
glitches the network. If you believe you need to kill processes that
act as gatekeepers for network traffic, you should make sure your
script is not subject to normal hangup handling (see the man pages
for nohup and batch for ways to do that)
Underkill: if you're committed to killing the active components of
LS before reboot to be sure (i.e. as if it were self-protective) you
need to also take out the Little Snitch Daemon process and unload
the kernel extension. There are also logs, caches, prefs, and
support files in the user-specific Library trees.
Not running as root: killing Little Snitch Daemon, unloading the
kext, removing most (if not all) of the system-wide components,
removing user-specific support files for multiple users, and
rebooting all require root.
Running reboot -q: Don't do that. It's safer on modern MacOS than it historically has been, but it can still be trouble. Better
to use  shutdown -r +1 "Rebooting for software change" which gives
a minute grace period, posts that message to any interactive shells,
and uses the proper launchd mechanisms to shut everything down. If
you want to be less polite, use "now" and/or no message.