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.com


Signed-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>