cciss: print max outstanding commands as a hex value

The max outstanding commands is being printed with a 0x prefix to
suggest it is a hex value, when in fact the integer decimal %d format
specifier is being used and this is a bit confusing. Use %x instead to
match the proceeding 0x prefix.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>