[PATCH v3] checkpatch: avoid COMMIT_LOG_LONG_LINE warning for signature tags

[Aditya Srivastava]

Currently checkpatch warns us for long lines in commits even for
signature tag lines.

Generally these lines exceed the 75-character limit because of:
1) long names and long email address
2) some comments on scoped review and acknowledgement, i.e., for a
dedicated pointer on what was reported by the identity in 'Reported-by'
3) some additional comments on CC: stable@xxxxxxxx tags

Exclude signature tag lines from this class of warning.

There were 1896 COMMIT_LOG_LONG_LINE warnings in v5.6..v5.8 before this
patch application and 1879 afterwards.

A quick manual check found all the dropped warnings related to signature
tags.

Signed-off-by: Aditya Srivastava <yashsri421@xxxxxxxxx>
---
Changes in v2:
modify commit message: remove specific commit example, add cause of the warning instead

Changes in v3:
modify commit message: minor english fix; remove difference count, add relative counts instead

 scripts/checkpatch.pl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index ac7e5ac80b58..f2369ac29d50 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -2961,8 +2961,8 @@ sub process {
 					# file delta changes
 		      $line =~ /^\s*(?:[\w\.\-]+\/)++[\w\.\-]+:/ ||
 					# filename then :
-		      $line =~ /^\s*(?:Fixes:|Link:)/i ||
-					# A Fixes: or Link: line
+		      $line =~ /^\s*(?:Fixes:|Link:|$signature_tags)/i ||
+					# A Fixes: or Link: line or signature tag line
 		      $commit_log_possible_stack_dump)) {
 			WARN("COMMIT_LOG_LONG_LINE",
 			     "Possible unwrapped commit description (prefer a maximum 75 chars per line)\n" . $herecurr);
-- 
2.17.1