In the FreeBSD kernel the strdup signature is:
```
char *strdup(const char *__restrict, struct malloc_type *);
```
It's unfortunate that the developers have chosen to change
the signature of libc functions - but it's what I have to
deal with.
Reviewed-by: Jorgen Lundman <lundman@lundman.net>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Matt Macy <mmacy@FreeBSD.org>
Closes#9433
e4f5fa1229