Input: ucb1400_ts - fix a misleading function name

The driver for UCB1400 touchscreen controllers contains a function named
ucb1400_ts_pen_down(), but it returns 0 if the pen is down and 1 if it's up.
This causes confusion, especially since it's used as a boolean truth value
later in the code. This patch renames it.
Signed-off-by: Hans J. Koch <hjk@linutronix.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>

drivers/input/touchscreen/ucb1400_ts.c

@@ -128,9 +128,10 @@ static inline unsigned int ucb1400_ts_read_yres(struct ucb1400_ts *ucb)
 	return ucb1400_adc_read(ucb->ac97, 0, adcsync);
 }
 
-static inline int ucb1400_ts_pen_down(struct snd_ac97 *ac97)
+static inline int ucb1400_ts_pen_up(struct snd_ac97 *ac97)
 {
 	unsigned short val = ucb1400_reg_read(ac97, UCB_TS_CR);
+
 	return val & (UCB_TS_CR_TSPX_LOW | UCB_TS_CR_TSMX_LOW);
 }
 
@@ -209,7 +210,7 @@ static int ucb1400_ts_thread(void *_ucb)
 
 		msleep(10);
 
-		if (ucb1400_ts_pen_down(ucb->ac97)) {
+		if (ucb1400_ts_pen_up(ucb->ac97)) {
 			ucb1400_ts_irq_enable(ucb->ac97);
 
 			/*