Fix cross-endian ELF note file / memory conversion

[emaste]

Summary

The problem was identified in r273443 but the fix was applied to the wrong place. The sizes are in native order after swapping for the file to memory case, and before swapping in the memory to file case.

[marcel]

The first part of the diff is wrong because ROUNDUP2 is called *after* the bytes are swapped. That's exactly the thing you can't do that was fixed by my commit. The second part is correct in that it fixes exactly this problem.

[emaste]

In D1257#6, @marcel wrote:

The first part of the diff is wrong because ROUNDUP2 is called *after* the bytes are swapped.

ROUNDUP2 has to be called with the values in native endianness, which is after swapping in the file-to-memory case.

[marcel]

Ah yes. The first part is in the reader. One needs to swap first.

[emaste]

Closed by commit rS275430 (authored by @emaste).