Remove netroot check in cmdline parsing code

Relax the rules for kdump, we don't specify netroot in kdump.

Cc: Harald Hoyer <harald@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>

modules.d/40network/parse-vlan.sh

@@ -9,9 +9,6 @@
 
 # Check if vlan parameter is valid
 if getarg vlan= >/dev/null ; then
-    if [ -z "$netroot" ] ; then
-        die "No netboot configured, vlan is invalid"
-    fi
     :
 fi