vmx: shortcut earlier few 'ignore' cases in virVMXParseDisk()
vmx: shortcut earlier few 'ignore' cases in virVMXParseDisk()

Move earlier the checks for skipping a hard disk when parsing a CD-DROM,
and for skipping a CD-ROM when parsing a hard disk. This should have no
behaviour changes, and avoids to add repeated checks in following
commits.

Signed-off-by: Pino Toscano <7f561d60bf2df812acf624afe597ba9d84c2586d@redhat.com>
Reviewed-by: Ján Tomko <4cab11cfb98d3c937327354a78eb07dbb6ee2bc6@redhat.com>
Tested-by: Richard W.M. Jones <d9c0c1814229c9d7f78a7e860ff9791c82a22dba@redhat.com>

jardasgit/libvirt,zippy2/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,libvirt/libvirt,olafhering/libvirt,libvirt/libvirt,zippy2/libvirt,libvirt/libvirt,nertpinx/libvirt,jfehlig/libvirt,olafhering/libvirt,zippy2/libvirt,crobinso/libvirt,crobinso/libvirt,crobinso/libvirt,olafhering/libvirt,zippy2/libvirt,nertpinx/libvirt,jardasgit/libvirt,crobinso/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,fabianfreyer/libvirt,jfehlig/libvirt,jardasgit/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,nertpinx/libvirt,jardasgit/libvirt,nertpinx/libvirt,olafhering/libvirt,libvirt/libvirt,jfehlig/libvirt