Kill off poll_interruptions(); it is lethal when we're acting as a PXE

stack or INT 13 emulator etc.

src/core/pcmcia.c

@@ -48,7 +48,6 @@ struct	driver_interact_t driver[] = {
 void	sleepticks(int numticks ) {
 	u_int	tmo;
 	for (tmo = currticks()+numticks; currticks() < tmo; ) {
-                poll_interruptions();
         }
 	return;
 }