hyperv/storvsc: Reduce log verbosity

On some windows hosts TEST_UNIT_READY command will return
SRB_STATUS_ERROR and sense data "NOT READY asc:3a,1 (Medium
not present - tray closed)", this occurs periodically, and
not hurt anything else.  So, we prefer to ignore this kind
of errors.

Approved by:    re (delphij)
PR:             [[ https://bugs.freebsd.org/219973 | 219973 ]]
Submitted by:   Hongjiang Zhang <hongzhan microsoft com>
Sponsored by:   Microsoft
Differential Revision:  https://reviews.freebsd.org/D11271