ipr: don't log error messages when applications issues illegal requests

Failing Device information are logged when IOA firmware detected these
illegal request such as IOA firmware doesn't support inquiry with page
code 2. The patch fixes the issue.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Tested-by: Wen Xiong <wenxiong@linux.vnet.ibm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>