Compilation of the AVILA kernel failed because of two reasons:
- It needed curthread, which is defined through <sys/pcpu.h>.
- It still referred the softc's sc_mtx field, which has been replaced by
sc_lock three weeks ago.
To solve the first problem, I decided to include <sys/pcpu.h> in
<sys/sx.h>, which also seems to be done by <sys/mutex.h> and
<sys/rwlock.h>. Those header files also require curthread.
Approved by: jhb
b992b3ff38