arch/install.sh: fix cwd bug when running sudo
arch/install.sh: fix cwd bug when running sudo

`-i` was added to the sudo command a couple of commits ago to run the
command in the user's home directory because `git clone` seems to cd
into the repo, then cd out when done. This would fail when install.sh
was run from a directory the user doesn't have permissions for (e.g.
/root).  But for some reason, using `sudo -i` combines all the lines in
the string passed to `bash -c` into one line, so the first comment was
ending the sequence of commands early. Now just `cd ~` as our first
command instead of using -i.

tylerbrazier/linux