treewide: add missing error handling

Change-Id: I55ccf3ff490b58f6af93e665c668428acddc8d65
Reviewed-on: https://review.monogon.dev/c/monogon/+/3019
Vouch-Run-CI: Tim Windelschmidt <tim@monogon.tech>
Tested-by: Jenkins CI
Reviewed-by: Serge Bazanski <serge@monogon.tech>
diff --git a/build/bazel_cc_fix/main.go b/build/bazel_cc_fix/main.go
index ffd5edb..b115e50 100644
--- a/build/bazel_cc_fix/main.go
+++ b/build/bazel_cc_fix/main.go
@@ -328,6 +328,9 @@
 		log.Fatalf("failed to read compilation db: %v", err)
 	}
 	specRaw, err := os.ReadFile(*specPath)
+	if err != nil {
+		log.Fatalf("failed to read spec file: %v", err)
+	}
 	var spec ccfixspec.CCFixSpec
 	if err := prototext.Unmarshal(specRaw, &spec); err != nil {
 		log.Fatalf("failed to load spec: %v", err)