dix: unexport BasicComputeAcceleration()

only used locally within one source file, so unexport and make it static.

Signed-off-by: Enrico Weigelt, metux IT consult <info@metux.net>
Part-of: <https://gitlab.freedesktop.org/xorg/xserver/-/merge_requests/1347>

dix/ptrveloc.c

@@ -749,10 +749,11 @@ ApplyConstantDeceleration(DeviceVelocityPtr vel, double *fdx, double *fdy)
 /*
  * compute the acceleration for given velocity and enforce min_acceleration
  */
-double
-BasicComputeAcceleration(DeviceIntPtr dev,
-                         DeviceVelocityPtr vel,
-                         double velocity, double threshold, double acc)
+static double BasicComputeAcceleration(DeviceIntPtr dev,
+                                       DeviceVelocityPtr vel,
+                                       double velocity,
+                                       double threshold,
+                                       double acc)
 {
 
     double result;

include/ptrveloc.h

@@ -81,10 +81,6 @@ typedef struct _DeviceVelocityRec {
     } statistics;
 } DeviceVelocityRec, *DeviceVelocityPtr;
 
-extern _X_EXPORT double
-BasicComputeAcceleration(DeviceIntPtr dev, DeviceVelocityPtr vel,
-                         double velocity, double threshold, double acc);
-
 extern _X_EXPORT void
 FreeVelocityData(DeviceVelocityPtr vel);