pk-offline-update: Fix crash due to invalid g_auto declaration in swi…

…tch / case

'case PK_PROGRESS_TYPE_PERCENTAGE' is just a label and doesn't offer
any scope as such. So, 'tmp_perc' auto variable will be allocated in
the stack, but will not be initialized to 'NULL' for 'case:'
statements other than 'PK_PROGRESS_TYPE_PERCENTAGE', causing GLib to
consider the 'tmp_perc' garbage value as a valid memory address
allocated via 'g_malloc()', triggering an invalid 'free()' causing the
crash.

Rather than adding a scope '{}' within 'case', and causing a huge
noise in git diff, we just move the declaration to an upper scope.

client/pk-offline-update.c

@@ -113,6 +113,7 @@ pk_offline_update_progress_cb (PkProgress *progress,
 	PkStatusEnum status;
 	gint percentage;
 	g_autofree gchar *msg = NULL;
+	g_autofree gchar *tmp_perc = NULL;
 	g_autoptr(PkPackage) pkg = NULL;
 
 	switch (type) {
@@ -145,8 +146,6 @@ pk_offline_update_progress_cb (PkProgress *progress,
 				  pk_package_get_data (pkg));
 		break;
 	case PK_PROGRESS_TYPE_PERCENTAGE:
-		g_autofree gchar *tmp_perc = NULL;
-
 		g_object_get (progress, "percentage", &percentage, NULL);
 		if (percentage < 0)
 			return;