checkpatch: add fix option for LOGICAL_CONTINUATIONS

Currently, checkpatch warns if logical continuations are placed at the
start of a line and not at the end of previous line.

E.g., running checkpatch on commit 3485507f ("staging: bcm2835-camera:
Reduce length of enum names") reports:

  CHECK:LOGICAL_CONTINUATIONS: Logical continuations should be on the previous line
  +	if (!ret
  +	    && camera_port ==

Provide a simple fix by inserting logical operator at the last
non-comment, non-whitespace char of the previous line and removing from
current line, if both the lines are additions(ie start with '+')

Link: https://lkml.kernel.org/r/20201123102818.24364-1-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>