src: shellcheck-ify shell scripts

src/shared/generate-ip-protocol-list.sh

@@ -1,8 +1,9 @@
-#!/bin/sh
+#!/bin/bash
 # SPDX-License-Identifier: LGPL-2.1-or-later
 
 set -eu
+set -o pipefail
 
-$1 -dM -include netinet/in.h - </dev/null | \
-    awk '/^#define[ \t]+IPPROTO_[^ \t]+[ \t]+[^ \t]/ { print $2; }' | \
-    sed -e 's/IPPROTO_//'
+${1:?} -dM -include netinet/in.h - </dev/null | \
+       awk '/^#define[ \t]+IPPROTO_[^ \t]+[ \t]+[^ \t]/ { print $2; }' | \
+       sed -e 's/IPPROTO_//'