Sensors: Fix an improper type definition when loading compass gain.

To load compass gain with a correct type, we should fix it to 'int'.
This should be common fix but partial related to bug 7355959.

Bug: 7355959

Change-Id: I3514618a47cedd5354d1d4b26d30a8026e02e6f3
diff --git a/drivers/staging/iio/magnetometer/inv_ami306_ring.c b/drivers/staging/iio/magnetometer/inv_ami306_ring.c
index dbb5588..11287ef 100644
--- a/drivers/staging/iio/magnetometer/inv_ami306_ring.c
+++ b/drivers/staging/iio/magnetometer/inv_ami306_ring.c
@@ -50,7 +50,7 @@
 };
 
 /* function for loading compass calibration file. */
-static int access_cali_file(short *gain, int target)
+static int access_cali_file(int *gain, int target)
 {
 	char buf[256];
 	int ret;