properly fix umask handling

https://dev.openwrt.org/ticket/13752
https://dev.openwrt.org/ticket/13794

Signed-off-by: John Crispin <blogic@openwrt.org>

hotplug.c

@@ -80,6 +80,7 @@ static void mkdir_p(char *dir)
 
 static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
 {
+	unsigned int oldumask = umask(0);
 	static struct blobmsg_policy mkdev_policy[2] = {
 		{ .type = BLOBMSG_TYPE_STRING },
 		{ .type = BLOBMSG_TYPE_STRING },
@@ -104,6 +105,7 @@ static void handle_makedev(struct blob_attr *msg, struct blob_attr *data)
 				m | strtoul(blobmsg_data(tb[1]), NULL, 8),
 				makedev(atoi(major), atoi(minor)));
 	}
+	umask(oldumask);
 }
 
 static void handle_rm(struct blob_attr *msg, struct blob_attr *data)

main.c

@@ -68,7 +68,6 @@ int main(int argc, char **argv)
 			return usage(argv[0]);
 		}
 	}
-	umask(0);
 	uloop_init();
 	procd_signal();
 	if (getpid() != 1)

mkdev.c

@@ -47,12 +47,15 @@ static bool find_pattern(const char *name)
 
 static void make_dev(const char *path, bool block, int major, int minor)
 {
+	unsigned int oldumask = umask(0);
 	unsigned int _mode = mode | (block ? S_IFBLK : S_IFCHR);
+
 	DEBUG(2, "Creating %s device %s(%d,%d)\n",
 		block ? "block" : "character",
 		path, major, minor);
 
 	mknod(path, _mode, makedev(major, minor));
+	umask(oldumask);
 }
 
 static void find_devs(bool block)