Rollup merge of #149885 - inkreasing:push-ovrwrllvzvmw, r=joboet

replace addr_of_mut with &raw mut in maybeuninit docs

In the docs for `addr_of_mut` it says that the macro is "soft-deprecated" so maybe the std docs should stop recommending it.
I searched for other places where this is used, but didn't find any in public stable documentation.

Author: matthiaskrgr