tools/hv: reduce resouce usage in hv_get_dns_info helper

Remove the usage of cat. Replace the shell process with awk with 'exec'.
Also use a generic shell because no bash specific features will be used.

Signed-off-by: Olaf Hering <[e-mail]>
Acked-by: Wei Liu <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Wei Liu <[e-mail]>
Message-ID: <[e-mail]>

tools/hv/hv_get_dns_info.sh

···
-#!/bin/bash
+#!/bin/sh
 
 # This example script parses /etc/resolv.conf to retrive DNS information.
 # In the interest of keeping the KVP daemon code free of distro specific
···
 # this script can be based on the Network Manager APIs for retrieving DNS
 # entries.
 
-cat /etc/resolv.conf 2>/dev/null | awk '/^nameserver/ { print $2 }'
+exec awk '/^nameserver/ { print $2 }' /etc/resolv.conf 2>/dev/null