Use 3 argument open to avoid any issues with parsing
and silence perlcritic.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>

--- a/scripts/get_maintainer.pl	2014-05-26 12:47:35.039720690 -0700
+++ b/scripts/get_maintainer.pl	2014-05-26 13:27:52.000000000 -0700
@@ -426,7 +426,7 @@ foreach my $file (@ARGV) {
 	my $file_cnt = @files;
 	my $lastfile;
 
-	open(my $patch, "< $file")
+	open(my $patch, '<', $file)
 	    or die "$P: Can't open $file: $!\n";
 
 	# We can check arbitrary information before the patch