checkpatch: comment ends inside strings is most likely not an open comment

When we are detecting whether a comment is open when we start a hunk we
check for the first comment edge in the hunk and assume its inverse.
However if the hunk contains something like below, then we will assume
that a comment was open.  Update this heuristic to see if the comment edge
is obviously within double quotes and ignore it if so:

	foo(" */);

Signed-off-by: Andy Whitcroft <apw@shadowen.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>