HID: input: do not append a suffix if the name already has it

Or it creates some weird input names like:
"MI Dongle MI Wireless Mouse Mouse"

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

drivers/hid/hid-input.c

@@ -1516,6 +1516,7 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid,
 	struct hid_input *hidinput = kzalloc(sizeof(*hidinput), GFP_KERNEL);
 	struct input_dev *input_dev = input_allocate_device();
 	const char *suffix = NULL;
+	size_t suffix_len, name_len;
 
 	if (!hidinput || !input_dev)
 		goto fail;
@@ -1559,10 +1560,15 @@ static struct hid_input *hidinput_allocate(struct hid_device *hid,
 	}
 
 	if (suffix) {
-		hidinput->name = kasprintf(GFP_KERNEL, "%s %s",
-					   hid->name, suffix);
-		if (!hidinput->name)
-			goto fail;
+		name_len = strlen(hid->name);
+		suffix_len = strlen(suffix);
+		if ((name_len < suffix_len) ||
+		    strcmp(hid->name + name_len - suffix_len, suffix)) {
+			hidinput->name = kasprintf(GFP_KERNEL, "%s %s",
+						   hid->name, suffix);
+			if (!hidinput->name)
+				goto fail;
+		}
 	}
 
 	input_set_drvdata(input_dev, hid);