Debug overlay mislabels memory units

The debug display shows the memory usage using MB (Megabyte = 10^6 bytes) as the unit.

Expected behaviour:

The memory usage is displayed in Megabytes.

Actual behaviour:

In reality it displays MiB (Mebibyte = 2^20 bytes). I've verified that in code where divides the incoming number of bytes by 1024 twice.

And before you ask, yeah I know it's somewhat commonly used that way. But I do consider it an error and it contradicts the SI. I would be fixable by simply adding an "i" in the middle and could also help reduce misuse in other places.