Fix import-tars fix.

This heeds advice from our resident Perl expert to make sure
the script is not confused with a string that ends with /\n

Signed-off-by: Junio C Hamano <junkio@cox.net>

contrib/fast-import/import-tars.perl

@@ -52,7 +52,7 @@ foreach my $tar_file (@ARGV)
 			Z8 Z1 Z100 Z6
 			Z2 Z32 Z32 Z8 Z8 Z*', $_;
 		last unless $name;
-		next if $name =~ '/$';
+		next if $name =~ m{/\z};
 		$mode = oct $mode;
 		$size = oct $size;
 		$mtime = oct $mtime;