Discovery parsing of dmi FRU data broke when whitespace fix was introduced

[davidmonro]

Commit 7e4f111 (and 7f7d7db) attempted to fix the problem of dmu FRU data returning just whitespace for the product name field. Unfortunately rather than rejecting fields which are just whitespace, they reject fields containing any whitespace. This breaks for us, as our servers have a product name of "PRIMERGY CX2550 M4" so this change means that the MTM ends up containing the rather inscrutable part number, instead of a useful name.