fix: resolve multiple definition of verbose and remove unused variable err

[TbYangZ]

Summary

This PR fixes two build issues:

1. Multiple definition of verbose

   • Declared as extern in common_defines.h
   • Defined once in common_defines.c

2. Unused variable err

   • Removed the unused variable in tc_prog_kern.c: tc_init_e_func

Verification

Tested with:

make all -C ~/ONCache