Staging: ft1000: replace pr_err with dev_err

This patch replace pr_err with dev_err, when appropriate device
structure is found.

Issue found using the following Coccinelle script:

@r exists@
identifier f, s, i;
position p;
@@

f(...,struct s *i,...) {
<+...
when != i == NULL
pr_err@p(...);
...+>
}

@rr@
identifier r.s, fld;
@@

struct s {
	...
	struct device *fld;
	...
};

@@
identifier r.i, rr.fld;
position r.p;
@@
-pr_err@p
+dev_err
   (
+ i->fld,
...)
Signed-off-by: Haneen Mohammed <hamohammed.sa@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/ft1000/ft1000-usb/ft1000_usb.c

@@ -136,7 +136,7 @@ static int ft1000_probe(struct usb_interface *interface,
 
 	ret = request_firmware(&dsp_fw, "ft3000.img", &dev->dev);
 	if (ret < 0) {
-		pr_err("Error request_firmware()\n");
+		dev_err(interface->usb_dev, "Error request_firmware()\n");
 		goto err_fw;
 	}
 
@@ -164,7 +164,8 @@ static int ft1000_probe(struct usb_interface *interface,
 	pr_debug("pft1000info=%p\n", pft1000info);
 	ret = dsp_reload(ft1000dev);
 	if (ret) {
-		pr_err("Problem with DSP image loading\n");
+		dev_err(interface->usb_dev,
+			"Problem with DSP image loading\n");
 		goto err_load;
 	}