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.

PR: 219973
Submitted by: Hongjiang Zhang <hongzhan microsoft com>
MFC after: 3 days
Sponsored by: Microsoft
Differential Revision: https://reviews.freebsd.org/D11271