checkpatch: Remove --no-signoff option

All patches should have Signed-off-by line in commit message as
described in doc/collaboration/code/changes.rst.

Change-Id: Iba6bad47115fd5323a096fa58c2d0d8c5ec9db75
Signed-off-by: Szymon Janc <ext.szymon.janc@tieto.com>
1 file changed