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 <olaf@aepfle.de>
Acked-by: Wei Liu <wei.liu@kernel.org>
Link: https://lore.kernel.org/r/20241202120432.21115-1-olaf@aepfle.de


Signed-off-by: Wei Liu <wei.liu@kernel.org>
Message-ID: <20241202120432.21115-1-olaf@aepfle.de>