checkpatch: warn when missing newline in return sysfs_emit() formats

return sysfs_emit() uses should include a newline.

Suggest adding a newline when one is missing.
Add one using --fix too.

Link: https://lkml.kernel.org/r/aa1819fa5faf786573df298e5e2e7d357ba7d4ad.camel@perches.com


Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>