hw/nvme: fix invalid check on mcl

hw/nvme: fix invalid check on mcl

The number of logical blocks within a source range is converted into a
1s based number at the time of parsing. However, when verifying the copy
length we add one again, causing the check against MCL to fail in error.

Cc: qemu-stable@nongnu.org
Fixes: 381ab99d8587 ("hw/nvme: check maximum copy length (MCL) for COPY")
Reviewed-by: Minwoo Im <minwoo.im@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>
(cherry picked from commit 8c78015a55d84c016da6d5e41b6b5f618ecb25ab)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>