test: Use fabsl on float128
diff --git a/test/matrix-test.c b/test/matrix-test.c
index 0a5f203..cd8820c 100644
--- a/test/matrix-test.c
+++ b/test/matrix-test.c
@@ -201,8 +201,8 @@
             {
                 for (j = 0; j < 3; j++)
                 {
-                    double diff = fabs (result_f.v[j] -
-                                        pixman_fixed_to_float128 (result_i.v[j]));
+                    double diff = fabsl (result_f.v[j] -
+                                         pixman_fixed_to_float128 (result_i.v[j]));
 
                     if (is_affine && diff > (0.51 / 65536.0))
                     {