nit(hypercall): remove unnecessary .as_bytes() call

[n0toose]

See 'https://rust-lang.github.io/rust-clippy/master/index.html#needless_as_bytes'

[codecov]

Codecov Report

Attention: Patch coverage is 0% with 1 line in your changes missing coverage. Please review.

Project coverage is 71.55%. Comparing base (f6fe3df) to head (73f3d15).
Report is 1 commits behind head on main.

Files with missing lines	Patch %	Lines
src/hypercall.rs	0.00%	1 Missing ⚠️

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #813   +/-   ##
=======================================
  Coverage   71.55%   71.55%           
=======================================
  Files          21       21           
  Lines        3041     3041           
=======================================
  Hits         2176     2176           
  Misses        865      865           

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[jounathaen]

Thanks!