esx: Fix floppy.fileName handling in the vmx file parser

esx: Fix floppy.fileName handling in the vmx file parser

The vmx file parsing code was reporting errors when parsing floppy.fileName
entries if the filename didn't end in .flp. There is no such restriction in
ESX; even using the GUI to configure floppy filenames you can specify any
arbitrary file with any extension.

Fix by changing the vmx parsing code so that it uses the floppy.fileType
value to determine whether floppy.fileName refers to a block device or a
regular file.

Also remove code that would have generated an error if no floppy.fileName
was specified. This is not an error either.

Updated the floppy tests in vmx2xmltest.c and xml2vmxtest.c.