compat/solaris/make_sunver.pl: Use /usr/bin/env perl instead of /usr/bin/perl

This is how the other perl scripts in git call perl
Reviewed-by: NGanesh Ajjanagadde <gajjanag@mit.edu>
Signed-off-by: NMichael Niedermayer <michael@niedermayer.cc>

compat/solaris/make_sunver.pl

-#!/usr/bin/perl -w
+#!/usr/bin/env perl
 
 # make_sunver.pl
 #