fmsg: implement suspend in writer

This removes the requirement to call fmsg.Exit on every exit path, and enables direct use of the "log" package. However, fmsg.BeforeExit is still encouraged when possible to catch exit on suspended output.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/fpkg/bundle.go

@@ -2,10 +2,10 @@ package main
 
 import (
 	"encoding/json"
+	"log"
 	"os"
 
 	"git.gensokyo.uk/security/fortify/dbus"
-	"git.gensokyo.uk/security/fortify/internal/fmsg"
 	"git.gensokyo.uk/security/fortify/internal/system"
 )
 
@@ -63,18 +63,18 @@ func loadBundleInfo(name string, beforeFail func()) *bundleInfo {
 	bundle := new(bundleInfo)
 	if f, err := os.Open(name); err != nil {
 		beforeFail()
-		fmsg.Fatalf("cannot open bundle: %v", err)
+		log.Fatalf("cannot open bundle: %v", err)
 	} else if err = json.NewDecoder(f).Decode(&bundle); err != nil {
 		beforeFail()
-		fmsg.Fatalf("cannot parse bundle metadata: %v", err)
+		log.Fatalf("cannot parse bundle metadata: %v", err)
 	} else if err = f.Close(); err != nil {
-		fmsg.Printf("cannot close bundle metadata: %v", err)
+		log.Printf("cannot close bundle metadata: %v", err)
 		// not fatal
 	}
 
 	if bundle.ID == "" {
 		beforeFail()
-		fmsg.Fatal("application identifier must not be empty")
+		log.Fatal("application identifier must not be empty")
 	}
 
 	return bundle
@@ -82,7 +82,7 @@ func loadBundleInfo(name string, beforeFail func()) *bundleInfo {
 
 func formatHostname(name string) string {
 	if h, err := os.Hostname(); err != nil {
-		fmsg.Printf("cannot get hostname: %v", err)
+		log.Printf("cannot get hostname: %v", err)
 		return "fortify-" + name
 	} else {
 		return h + "-" + name