checkpatch: allow Closes tags with links

As a follow-up of a previous patch modifying the documentation to allow
using the "Closes:" tag, checkpatch.pl is updated accordingly.

checkpatch.pl now no longer complain when the "Closes:" tag is used by
itself:

  commit 76f381bb ("checkpatch: warn when unknown tags are used for links")

... or after the "Reported-by:" tag:

  commit d7f1d71e ("checkpatch: warn when Reported-by: is not followed by Link:")

Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/373
Link: https://lkml.kernel.org/r/20230314-doc-checkpatch-closes-tag-v4-4-d26d1fa66f9f@tessares.netSigned-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Acked-by: Joe Perches <joe@perches.com>
Cc: Andy Whitcroft <apw@canonical.com>
Cc: Bagas Sanjaya <bagasdotme@gmail.com>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: David Airlie <airlied@gmail.com>
Cc: Dwaipayan Ray <dwaipayanray1@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kai Wasserbäch <kai@dev.carbon-project.org>
Cc: Konstantin Ryabitsev <konstantin@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Cc: Thorsten Leemhuis <linux@leemhuis.info>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

scripts/checkpatch.pl

@@ -620,7 +620,7 @@ our $signature_tags = qr{(?xi:
 	Cc:
 )};
 
-our @link_tags = qw(Link);
+our @link_tags = qw(Link Closes);
 
 #Create a search and print patterns for all these strings to be used directly below
 our $link_tags_search = "";
@@ -3174,14 +3174,14 @@ sub process {
 				}
 			}
 
-# check if Reported-by: is followed by a Link:
+# check if Reported-by: is followed by a Closes: tag
 			if ($sign_off =~ /^reported(?:|-and-tested)-by:$/i) {
 				if (!defined $lines[$linenr]) {
 					WARN("BAD_REPORTED_BY_LINK",
-					     "Reported-by: should be immediately followed by Link: with a URL to the report\n" . $herecurr . "\n");
-				} elsif ($rawlines[$linenr] !~ m{^link:\s*https?://}i) {
+					     "Reported-by: should be immediately followed by Closes: with a URL to the report\n" . $herecurr . "\n");
+				} elsif ($rawlines[$linenr] !~ m{^closes:\s*https?://}i) {
 					WARN("BAD_REPORTED_BY_LINK",
-					     "Reported-by: should be immediately followed by Link: with a URL to the report\n" . $herecurr . $rawlines[$linenr] . "\n");
+					     "Reported-by: should be immediately followed by Closes: with a URL to the report\n" . $herecurr . $rawlines[$linenr] . "\n");
 				}
 			}
 		}