dm integrity: fix the maximum number of arguments

dm integrity: fix the maximum number of arguments

commit 17ffc193cdc6dc7a613d00d8ad47fc1f801b9bf0 upstream.

Advance the maximum number of arguments from 9 to 15 to account for
all potential feature flags that may be supplied.

Linux 4.19 added "meta_device"
(356d9d52e1221ba0c9f10b8b38652f78a5298329) and "recalculate"
(a3fcf7253139609bf9ff901fbf955fba047e75dd) flags.

Commit 468dfca38b1a6fbdccd195d875599cb7c8875cd9 added
"sectors_per_bit" and "bitmap_flush_interval".

Commit 84597a44a9d86ac949900441cea7da0af0f2f473 added
"allow_discards".

And the commit d537858ac8aaf4311b51240893add2fc62003b97 added
"fix_padding".

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>