libefivar: CodeQL Fixes

[jlduran]

Summary

Includes changes across the repo for the following CodeQL rules:

• cpp/comparison-with-wider-type
• cpp/overflow-buffer
• cpp/redundant-null-check-param
• cpp/uselesstest

Obtained from: https://github.com/tianocore/edk2/commit/b7735a087afce6a5157b61e5450b6848ed535a14

[imp]

Commit message from upstream sucks.

The vast majority of this change is to make CreateDeviceNode returning NULL survivable.

Plus a number of dubious changes that don't really help (the asserts inside if's really should have been deleted instead, since it was asserting that nobody ever passed in a NULL, though the wisdom of that is kinda sketchy given the rest of the code).

So not a huge fan, but it's upstream, and we'd get it the next time we did a bulk import anyway.

lib/libefivar/efivar-dp-format.c

1911

This assert is now never going to fire and is completely useless.

lib/libefivar/efivar-dp-parse.c

1041

Arguably, all these should use this sort of pattern.... but upstream is a bit inconsistent at the best of times.

3154

This one should have just been if Uri == NULL return too. This is correct, but confusing.

[jlduran]

Yes, it seems to be a recurring issue with EDK2. I'll modify the commit message to accommodate some this information. My main objective was to incorporate D49060. Thanks.