`QObject` and `QGadget` derives produce clippy warnings

[lylythechosenone]

In seemingly all situations, QGadget produces a clippy::transmute_ptr_to_ref warning.
In a struct with signals, QObject produces a clippy::useless_transmute for each signal.

For both of these, the transmute should be replaced. For the first, &*val can be used instead of transmute(val). For the second, val as *const _ can be used instead of transmute(val).