On ppc64le, TUNSETIFF happens to be 2147767498, which is bigger than
INT_MAX (2^31 - 1), and musl declares the second argument of ioctl()
as 'int', not 'unsigned long' like glibc does, probably because of how
POSIX specifies the equivalent argument, int dcmd, in posix_devctl(),
so gcc reports a warning:
tap.c: In function 'tap_ns_tun':
tap.c:1291:24: warning: overflow in conversion from 'long unsigned int' to 'int' changes value from '2147767498' to '-2147199798' [-Woverflow]
1291 | rc = ioctl(fd, TUNSETIFF, &ifr);
| ^~~~~~~~~
We don't care about that overflow, so explicitly cast TUNSETIFF to
int.
Signed-off-by: Stefano Brivio