ODROID-XU3/4: Fix wiringPiISR.

If a pin is exported, ISR does not work on XU4.
We will clear pin before using with wiringPiISR function.

Signed-off-by: Steve Jeong <how2soft@gmail.com>
Change-Id: Ibc747fe30fda20253eb77d9bbe5f6bcc8c2180b8
diff --git a/wiringPi/wiringPi.c b/wiringPi/wiringPi.c
index 4d7b239..42e86ad 100644
--- a/wiringPi/wiringPi.c
+++ b/wiringPi/wiringPi.c
@@ -894,6 +894,14 @@
 	if (mode != INT_EDGE_SETUP) {
 		sprintf (pinS, "%d", GpioPin) ;
 
+		char temp[64];
+		sprintf(temp, "/sys/class/gpio/gpio%d", GpioPin);
+		if (access(temp, F_OK) == 0) {
+			FILE *unexport = fopen("/sys/class/gpio/unexport", "w");
+			fprintf (unexport, "%d\n", GpioPin);
+			fclose(unexport);
+		}
+
 		FILE *export, *direct, *edge;
 		int count;