removed warning

src/c_interface/tensor_field.c

@@ -66,7 +66,7 @@ void tensor_field_deallocate(tensor_field field) {
 }
 
 void tensor_field_from_futhark_f32_4d_inplace(struct futhark_f32_4d *f, struct futhark_context *ctx, tensor_field field) {
-    int64_t *shape = futhark_shape_f32_4d(ctx, f);
+    const int64_t *shape = futhark_shape_f32_4d(ctx, f);
     fint nx = shape[0];
     fint ny = shape[1];
     fint nz = shape[2];
@@ -99,7 +99,7 @@ void tensor_field_compute_norm_inplace(tensor_field field, scalar_field norm) {
 }
 
 tensor_field tensor_field_from_futhark_f32_4d(struct futhark_f32_4d *f, struct futhark_context *ctx) {
-    int64_t *shape = futhark_shape_f32_4d(ctx, f);
+    const int64_t *shape = futhark_shape_f32_4d(ctx, f);
     fint nx = shape[0];
     fint ny = shape[1];
     fint nz = shape[2];