Change get_if_raw_hwaddr to get_if_hwaddr (#4802)

I assume there was an update somewhere along the lines and the documentation here wasn't updated to reflect the new function name/functionality

Author: pemanpro

doc/scapy/usage.rst

@@ -1681,7 +1681,7 @@ Solution
 Use Scapy to send a DHCP discover request and analyze the replies::
 
     >>> conf.checkIPaddr = False
-    >>> fam,hw = get_if_raw_hwaddr(conf.iface)
+    >>> hw = get_if_hwaddr(conf.iface)
     >>> dhcp_discover = Ether(dst="ff:ff:ff:ff:ff:ff")/IP(src="0.0.0.0",dst="255.255.255.255")/UDP(sport=68,dport=67)/BOOTP(chaddr=hw)/DHCP(options=[("message-type","discover"),"end"])
     >>> ans, unans = srp(dhcp_discover, multi=True)      # Press CTRL-C after several seconds
     Begin emission: