sys_modstat copyout non-NUL-terminated module name when name>=MAXMODNAME

Summary

sys_modstat(:348-351) namelen=strlen+1 clamped to MAXMODNAME. When mod name>=MAXMODNAME bytes, copyout writes MAXMODNAME with no NUL. User buffer is char[MAXMODNAME]. No kernel leak. Userland consumer treating as C string may over-read.