use interpolator Macro

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@44525 15284696-431f-4ddb-bdfa-cd5b030d7da7

lib/lidar/zones.c

@@ -220,7 +220,7 @@ int P_get_BandWidth(int interpolator, int nsplines)
 {
     /* Returns the interpolation matrixes BandWidth dimension */
 
-    if (interpolator == 1) {
+    if (interpolator == P_BILINEAR) {
 	return (2 * nsplines + 1);
     }
     else {