Apply suggestion from @aduh95

Co-authored-by: Antoine du Hamel <duhamelantoine1995@gmail.com>

Author: jasnell

lib/rules/signed-off-by.js

@@ -39,8 +39,8 @@ export default {
     const signoffPattern = /^Signed-off-by: /i
     const validSignoff = /^Signed-off-by: .+ <[^@]+@[^@]+\.[^@]+>/i
     const signoffs = parsed.body
+      .filter((line) => signoffPattern.test(line))
       .map((line, i) => [line, i])
-      .filter(([line]) => signoffPattern.test(line))
 
     if (signoffs.length === 0) {
       context.report({