Ignore Device Paths in the Boot Info that don't have Media path
nodes. These show up in default entries on SuperMicro motherboards and
elsewhere. Before, we couldn't find a block device associated with the
device path and return BAD_CHOICE which was an instant
failure. However, a VendHw node isn't specifc, so when we don't find a
media path, return NOT_SPECIFIC so that the rest of the algorithms
work.

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