Remove unused variables.

api.c

@@ -3089,7 +3089,6 @@ static int itemstats(struct io_data *io_data, int i, char *id, struct cgminer_st
 	if (cgpu) {
 #ifdef USE_USBUTILS
 		char details[256];
-		int val;
 
 		if (cgpu->usbinfo.pipe_count)
 			snprintf(details, sizeof(details),

usbutils.c

@@ -2345,7 +2345,6 @@ int _usb_read(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_t
 	int endlen;
 	unsigned char *ptr, *usbbuf = cgpu->usbinfo.bulkbuf;
 	size_t usbbufread;
-	int lock_wait;
 
 	DEVRLOCK(cgpu, pstate);
 
@@ -2620,7 +2619,6 @@ int _usb_write(struct cgpu_info *cgpu, int intinfo, int epinfo, char *buf, size_
 	double max, done;
 	__maybe_unused bool first = true;
 	int err, sent, tot, pstate;
-	int lock_wait;
 
 	DEVRLOCK(cgpu, pstate);