[ibex_tracer] Void cast function calls
[ibex_tracer] Void cast function calls

...whose return value is ignored. This cleans up a compile time warning.

Signed-off-by: Srikrishna Iyer <2803d640feace36379942447842f26c7747b4dc3@google.com>

lowRISC/ibex,AmbiML/ibex,lowRISC/ibex,AmbiML/ibex,AmbiML/ibex,lowRISC/ibex,lowRISC/ibex,AmbiML/ibex