Prevent Magisk database race condition

The database should only be accessed by a single process, which is magiskd.
This means 'magisk --sqlite [SQL]' has to be updated to pass the SQL command to the daemon.
In addition, open the database connection with SQLITE_OPEN_FULLMUTEX to support multithread in magiskd.

native/jni/daemon/magisk.cpp

@@ -113,7 +113,11 @@ int magisk_main(int argc, char *argv[]) {
 		write_int(fd, BOOT_COMPLETE);
 		return read_int(fd);
 	} else if (strcmp(argv[1], "--sqlite") == 0) {
-		return exec_sql(argv[2]);
+		int fd = connect_daemon();
+		write_int(fd, SQLITE_CMD);
+		write_string(fd, argv[2]);
+		send_fd(fd, STDOUT_FILENO);
+		return read_int(fd);
 	}
 
 	usage();