kbuild/btf: Propagate CONFIG_WERROR to resolve_btfids

Use CONFIG_WERROR to also fail on warnings emitted by resolve_btfids.
Allow the CI bots to prevent the introduction of new warnings.

Signed-off-by: Thomas Weißschuh <[email protected]>
Signed-off-by: Daniel Borkmann <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: t-8ch

scripts/link-vmlinux.sh

@@ -283,7 +283,11 @@ vmlinux_link vmlinux
 # fill in BTF IDs
 if is_enabled CONFIG_DEBUG_INFO_BTF; then
 	info BTFIDS vmlinux
-	${RESOLVE_BTFIDS} vmlinux
+	RESOLVE_BTFIDS_ARGS=""
+	if is_enabled CONFIG_WERROR; then
+		RESOLVE_BTFIDS_ARGS=" --fatal_warnings "
+	fi
+	${RESOLVE_BTFIDS} ${RESOLVE_BTFIDS_ARGS} vmlinux
 fi
 
 mksysmap vmlinux System.map