perf script stackcollapse: Remove reference to the perl interpreter

It is ignored and this is actually a python script, not a perl one.
Reported-by: NBrendan Gregg <brendan.d.gregg@gmail.com>
Cc: Jiri Olsa <jolsa@kernel.org>
Cc: Milian Wolff <milian.wolff@kdab.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Link: http://lkml.kernel.org/n/tip-0w4bpbqd79v3sl34jvpr11v0@git.kernel.orgSigned-off-by: NArnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/scripts/python/stackcollapse.py

-#!/usr/bin/perl -w
-#
 # stackcollapse.py - format perf samples with one line per distinct call stack
 #
 # This script's output has two space-separated fields.  The first is a semicolon