sispmctl: fix compilation error with musl

Unpatched compile fails because <sys/types.h> is not included
in <usb.h> (provided by "libusb-compat") and consequently
the 'u_int*_t' types are not found.

This should probably better be fixed in the core "libusb-compat"
package instead.

Signed-off-by: Richard Kunze <richard.kunze@web.de>