nvme: delete outdated comments about xfer size
nvme: delete outdated comments about xfer size

This is calculated elsewhere now, so remove the comments around
nvme_qpair_construct calls.

Change-Id: I2dc4956a9e250b88e62038bc55cdd315940ad391
Signed-off-by: Daniel Verkamp <7da385bb5c986b932d183f3a13d271ee45d259b4@intel.com>

changhuilin/spdk,changhuilin/spdk,changhuilin/spdk