checkasm: Increase the tolerance for ac3_sum_square_butterfly_float

Increase the tolerance from 10 ulp to 11 ulp. This fixes occasional
errors for some inputs; the errors could be reproduced on
aarch64/neon builds, with "checkasm --test=ac3dsp 3446175925".

Signed-off-by: Martin Storsjö <martin@martin.st>

tests/checkasm/ac3dsp.c

@@ -181,7 +181,7 @@ static void check_ac3_sum_square_butterfly_float(AC3DSPContext *c) {
         call_ref(v1, lt, rt, ELEMS);
         call_new(v2, lt, rt, ELEMS);
 
-        if (!float_near_ulp_array(v1, v2, 10, 4))
+        if (!float_near_ulp_array(v1, v2, 11, 4))
             fail();
 
         bench_new(v2, lt, rt, ELEMS);