checkpatch: add fix option for GERRIT_CHANGE_ID

Currently, whenever a Gerrit Change-Id is present in a commit,
checkpatch.pl warns to remove the Change-Id before submitting the patch.

E.g., running checkpatch on commit adc311a5 ("iwlwifi: bump FW
API to 53 for 22000 series") reports this error:

  ERROR: Remove Gerrit Change-Id's before submitting upstream
  Change-Id: I5725e46394f3f53c3069723fd513cc53c7df383d

Provide a simple fix option by simply deleting the indicated line.

Link: https://lkml.kernel.org/r/20201030114447.24199-1-yashsri421@gmail.comSigned-off-by: Aditya Srivastava <yashsri421@gmail.com>
Acked-by: Joe Perches <joe@perches.com>
Cc: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

@@ -2852,8 +2852,11 @@ sub process {
 
 # Check for Gerrit Change-Ids not in any patch context
 		if ($realfile eq '' && !$has_patch_separator && $line =~ /^\s*change-id:/i) {
-			ERROR("GERRIT_CHANGE_ID",
-			      "Remove Gerrit Change-Id's before submitting upstream\n" . $herecurr);
+			if (ERROR("GERRIT_CHANGE_ID",
+			          "Remove Gerrit Change-Id's before submitting upstream\n" . $herecurr) &&
+			    $fix) {
+                                fix_delete_line($fixlinenr, $rawline);
+                        }
 		}
 
 # Check if the commit log is in a possible stack dump