components/9990-networking.sh: Add shellcheck override

To make `components/9990-networking.sh` shellcheck clean, add an
override for specifying `HWADDR`, which is used by `do_iscsi` from
`9990-mount-iscsi.sh`. Run shellcheck:

```
shellcheck -e SC1090 components/9990-networking.sh
```

Signed-off-by: Benjamin Drung <benjamin.drung@cloud.ionos.com>

diff --git a/components/9990-networking.sh b/components/9990-networking.sh
index 9cc3674..88bad20 100755 (executable)
--- a/components/9990-networking.sh
+++ b/components/9990-networking.sh
@@ -128,6 +128,8 @@ do_netsetup ()
 
                if [ -n "${interface}" ]
                then
+                       # HWADDR used by do_iscsi from 9990-mount-iscsi.sh
+                       # shellcheck disable=SC2034
                        HWADDR="$(cat "/sys/class/net/${interface}/address")"
                fi