[cuda][null][common] fix a few coverity issues

[pbalcer]

This should fix all non-test related coverity issues except for:
https://scan7.scan.coverity.com/reports.htm#v21214/p15954/fileInstanceId=155217701&defectInstanceId=19136875&mergedDefectId=1574236, which is a race in the HIP adapter - that looks like it might be a false positive, but I'm not sure.

[codecov-commenter]

Codecov Report

Attention: 4 lines in your changes are missing coverage. Please review.

❗ No coverage uploaded for pull request base (main@c90c8be). Click here to learn what that means.
Report is 2 commits behind head on main.

Files	Patch %	Lines
source/adapters/null/ur_null.cpp	0.00%	2 Missing ⚠️
source/common/ur_util.hpp	0.00%	2 Missing ⚠️

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Additional details and impacted files

@@           Coverage Diff           @@
##             main    #1203   +/-   ##
=======================================
  Coverage        ?   15.73%           
=======================================
  Files           ?      223           
  Lines           ?    31465           
  Branches        ?     3555           
=======================================
  Hits            ?     4951           
  Misses          ?    26463           
  Partials        ?       51           

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[pbalcer]

intel/llvm#12207

[aarongreig]

I'll look into the hip issue, it looks a lot like a few other issues that came up around queue that I already marked as false positives