Fix Superuser on 64 bits target

[tombriden]

• An export to "/system/lib" is not required and cause problems as this is a 32 bits lib dir only
• When writing to socket, datatype size_t was used, which is 4 bytes on 32 bits target and 8 bytes on 64 bits. Superuser expects it as a 4 bytes length. So, it was replaced by "uint32_t" datatype