checkpatch: warn only on "space before semicolon" at end of line

The "space before a non-naked semicolon" test has unwanted output when
used in "for ( ;; )" loops.

Make the test work only on end-of-line statement termination semicolons.

Signed-off-by: Joe Perches <joe@perches.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>