get_maintainer: repair STDIN usage

Commit 22dd5b0 (fix perlcritic warnings)
broke the ability to handle STDIN because the three argument version of
open() cannot handle standard IO-streams (which is mentioned in
PerlBestPractices, too).

Signed-off-by: Wolfram Sang <[email protected]>
Cc: Stephen Hemminger <[email protected]>
Acked-by: Joe Perches <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

scripts/get_maintainer.pl

@@ -284,7 +284,7 @@
 	my $file_cnt = @files;
 	my $lastfile;
 
-	open(my $patch, '<', $file)
+	open(my $patch, "< $file")
 	    or die "$P: Can't open $file: $!\n";
 	while (<$patch>) {
 	    my $patch_line = $_;