Simulate NMR API failures: Fix SIGSEGV crashes

[shpalani]

Description

This PR addresses 3 crashes when fault injection is enabled in nmr apis.

Please see the details of call stack in #2101

Testing

Do any existing tests cover this change? Yes
Are new tests needed? No

Documentation

Is there any documentation impact for this change? No

[codecov]

Codecov Report

Merging #2268 (ee6669c) into main (21300ed) will decrease coverage by 0.05%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main    #2268      +/-   ##
==========================================
- Coverage   83.61%   83.57%   -0.05%     
==========================================
  Files         151      151              
  Lines       28276    28279       +3     
==========================================
- Hits        23643    23633      -10     
- Misses       4633     4646      +13     

Impacted Files	Coverage Δ
libs/execution_context/ebpf_native.c	90.47% <100.00%> (-0.39%)	⬇️
libs/execution_context/ebpf_program.c	82.85% <100.00%> (+0.01%)	⬆️
libs/platform/user/nmr_impl.cpp	87.04% <100.00%> (-0.39%)	⬇️

... and 2 files with indirect coverage changes

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[dthaler]

Code doesn't match SAL annotation.
Please fix one or the other.

Updated