Make sure to not skip any argument when converting from deprecated
+POS1, -POS2 to -kPOS1,POS2, so that sort +0n gets translated to sort -k1,1n
as it is expected

PR:		193994
Submitted by:	rodrigo
MFC after:	3 days


git-svn-id: svn+ssh://svn.freebsd.org/base/head@272398 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f