strlcpy ensure the destination is NUL-terminated, and also fix warning:
```c
task/task_prctl.c:138:15: warning: 'strncpy' output may be truncated copying 30 bytes from a string of length 31 [-Wstringop-truncation]
138 | strncpy(name, tcb->name, CONFIG_TASK_NAME_SIZE - 1);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
```
Signed-off-by: Huang Qi <huangqi3@xiaomi.com>