udev resource should ignore "virtual" disk devices

Many servers are presented with a "virtual" disk device from the BMC. These are used to pass files from a remote workstation onto the server filesystem via the BMC, but they are not real block devices. THe OS is just tricked into thinking they are.

The udev_resource script currently identifies these and assumes they are real and creats DISK objects based on them. This causes disk tests to be run against these fake devices, which ultimately fail and are unnecessary.

udev_resource (or the parser) should ignore these based on their identification (they almost always appear as a Virtual BLAH under Product:

path: /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/host7/target7:0:0/7:0:0:1
name: sdb
bus: scsi
category: DISK
driver: sd
product: Virtual FDD/HDD
vendor: Linux
product_slug: Virtual_FDD_HDD
vendor_slug: Linux

path: /devices/pci0000:00/0000:00:1a.0/usb1/1-1/1-1.2/1-1.2:1.0/host7/target7:0:0/7:0:0:2
name: sdc
bus: scsi
category: DISK
driver: sd
product: Virtual Floppy
vendor: Linux
product_slug: Virtual_Floppy
vendor_slug: Linux