run: fix two minor memory leaks

run: fix two minor memory leaks

```
==19541== 8 bytes in 1 blocks are still reachable in loss record 1 of 3
==19541==    at 0x4841744: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==19541==    by 0x50125C9: strdup (strdup.c:42)
==19541==    by 0x4C55925: getusername_malloc (user-util.c:154)
==19541==    by 0x1121D6: parse_argv_sudo_mode (run.c:1098)
==19541==    by 0x123B13: run (run.c:3032)
==19541==    by 0x124198: main (run.c:3100)
==19541==
==19541== 11 bytes in 1 blocks are still reachable in loss record 2 of 3
==19541==    at 0x4841744: malloc (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==19541==    by 0x50125C9: strdup (strdup.c:42)
==19541==    by 0x112A9C: parse_argv_sudo_mode (run.c:1182)
==19541==    by 0x123B13: run (run.c:3032)
==19541==    by 0x124198: main (run.c:3100)
```