[media] xc5000: Remove the global mutex lock at xc5000 firmware init

As reported by Devin Heitmueller <dheitmueller@kernellabs.com>:

> It seems like a change such as this could significantly change the
> timing of tuner initialization if you have multiple xc5000 based
> products that might have a slow i2c bus.  Was that intentional?

After discussed with Eddi de Pierri <eddi@depieri.net>, it was pointed that
the change was not intentional, and it was just a trial while developing
the patches that add support for HVR-930C.

So, remove this hack.
Reported-by: Devin Heitmueller <dheitmueller@kernellabs.com>
Acked by: Eddi de Pierri <eddi@depieri.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/common/tuners/xc5000.c

@@ -1004,8 +1004,6 @@ static int xc_load_fw_and_init_tuner(struct dvb_frontend *fe)
 	struct xc5000_priv *priv = fe->tuner_priv;
 	int ret = 0;
 
-	mutex_lock(&xc5000_list_mutex);
-
 	if (xc5000_is_firmware_loaded(fe) != XC_RESULT_SUCCESS) {
 		ret = xc5000_fwupload(fe);
 		if (ret != XC_RESULT_SUCCESS)
@@ -1025,8 +1023,6 @@ static int xc_load_fw_and_init_tuner(struct dvb_frontend *fe)
 	/* Default to "CABLE" mode */
 	ret |= xc_write_reg(priv, XREG_SIGNALSOURCE, XC_RF_MODE_CABLE);
 
-	mutex_unlock(&xc5000_list_mutex);
-
 	return ret;
 }