tests: drivers: audio: pdm_loopback: fix incorrect error code

Errno codes are returned now.

Signed-off-by: Nikodem Kastelik <[email protected]>

Author: nika-nordic

tests/drivers/audio/pdm_loopback/src/main.c

@@ -245,7 +245,7 @@ ZTEST(pdm_loopback, test_pdm_clk_frequency)
 	timer_config.mode      = NRF_TIMER_MODE_COUNTER;
 
 	ret = nrfx_timer_init(&timer_instance, &timer_config, timer_handler);
-	zassert_true(ret == NRFX_SUCCESS,
+	zassert_true(ret == 0,
 		     "TIMER initialization failed, return code = 0x%08X", ret);
 
 	nrfx_timer_enable(&timer_instance);