basic/arphrd: stop discriminating against NETROM and CISCO

ARPHRD_NETROM was excluded, most likely just because it is protocol No. 0,
and ARPHRD_CISCO was reported under its alias name "HDLC". Let's just
allow defined aliases under the main name.

src/basic/arphrd-to-name.awk

@@ -2,7 +2,7 @@ BEGIN{
         print "const char *arphrd_to_name(int id) {"
         print "        switch(id) {"
 }
-!/CISCO|NETROM/ {
+!/^HDLC$/ {
         printf "        case ARPHRD_%s: return \"%s\";\n", $1, $1
 }
 END{

src/test/test-arphrd-list.c

@@ -22,7 +22,6 @@ int main(int argc, const char *argv[]) {
         }
 
         assert_se(arphrd_to_name(ARPHRD_VOID + 1) == NULL);
-        assert_se(arphrd_to_name(0) == NULL);
         assert_se(arphrd_from_name("huddlduddl") == -EINVAL);
         assert_se(arphrd_from_name("") == -EINVAL);