fabrics: add udev rule to avoid renaming nbft interfaces

fabrics: add udev rule to avoid renaming nbft interfaces

In the initramfs, the interface naming is taken care of by dracut.
But there are various network-interface-naming policies in place which
may attempt to rename the interface, causing confusion and possibly
wrong interface parameters.

Add an udev rule that avoids renaming any network interface that
has been assigned a name nbft$N, which is by convention the naming
scheme that is used for NBFT device in the initramfs.

Note: The simpler 'NAME:="%k"' directive doesn't work because udev rejects
it ('Ignoring NAME="%k", as it will take no effect.'). The ":=" syntax makes
sure the interface isn't renamed any more by later rules. "INTERFACE" is set
by the kernel in the "add" uevent for a network interface.

Signed-off-by: Martin Wilck <mwilck@suse.com>