scripts/recordmcount.pl: Make vim and emacs indent the same

By default, emacs indents Perl files with 4 spaces, but will use tabs
where 8 spaces are used. Add a vim command of softtabstop=4, to make vim
behave the same. This should remove the issue of developers using vim
having causing different indentation.

"John (Warthog9) Hawley" <warthog9@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>