fix(EOF): ext*call return values

[rakita]

return value got changed from legacy calls.

0 if the call was successful.
1 if the call has reverted (also can be pushed earlier in a light failure scenario).
2 if the call has failed.

[github-actions]

Valgrind Results:

==3754== Cachegrind, a cache and branch-prediction profiler
==3754== Copyright (C) 2002-2017, and GNU GPL'd, by Nicholas Nethercote et al.
==3754== Using Valgrind-3.18.1 and LibVEX; rerun with -h for copyright info
==3754== Command: target/release/snailtracer
==3754== 
--3754-- warning: L3 cache found, using its data for the LL simulation.
Running snailtracer example!
elapsed: 1.840988222s
==3754== 
==3754== I   refs:      430,648,121
==3754== I1  misses:          3,175
==3754== LLi misses:          2,805
==3754== I1  miss rate:        0.00%
==3754== LLi miss rate:        0.00%
==3754== 
==3754== D   refs:      202,359,248  (131,534,917 rd   + 70,824,331 wr)
==3754== D1  misses:        338,763  (    198,520 rd   +    140,243 wr)
==3754== LLd misses:        137,816  (      4,329 rd   +    133,487 wr)
==3754== D1  miss rate:         0.2% (        0.2%     +        0.2%  )
==3754== LLd miss rate:         0.1% (        0.0%     +        0.2%  )
==3754== 
==3754== LL refs:           341,938  (    201,695 rd   +    140,243 wr)
==3754== LL misses:         140,621  (      7,134 rd   +    133,487 wr)
==3754== LL miss rate:          0.0% (        0.0%     +        0.2%  )