[arp_update]: Fix hardcoded vlan (#12566)

Typo in prior PR #11919 hardcodes Vlan name. Change command to use the $vlan variable instead

Signed-off-by: Lawrence Lee <[email protected]>

files/scripts/arp_update

@@ -58,7 +58,7 @@ while /bin/true; do
         # generates the following command for each failed or incomplete IPv6 neighbor
         # ip neigh replace <neighbor IPv6> dev <VLAN name> nud incomplete
         neigh_replace_template="sed -e 's/^/ip neigh replace /' -e 's/,/ dev /' -e 's/$/ nud incomplete;/'" 
-        ip_neigh_replace_cmd="ip -6 neigh show | grep -v fe80 | grep Vlan1000 | grep -E 'FAILED|INCOMPLETE' | cut -d ' ' -f 1,3 --output-delimiter=',' | $neigh_replace_template"
+        ip_neigh_replace_cmd="ip -6 neigh show | grep -v fe80 | grep $vlan | grep -E 'FAILED|INCOMPLETE' | cut -d ' ' -f 1,3 --output-delimiter=',' | $neigh_replace_template"
         eval `eval $ip_neigh_replace_cmd`
 
         # on dual ToR devices, try to resolve failed neighbor entries since