[PATCH] usb: gadget: function: Simplify error messaging in printer open/close

[Andrzej Pietrasiewicz <andrzej.p@collabora.com>]

Don't issue any messages if printer_open() is successful.
Also don't issue them if unsuccessful - the error code is propagated
to the calling layers and should be acted on appropriately there. Just as
it is with the -ENODEV case.

For those who really want this message leave an option to compile-in
with composite framework's VDBG() by uncommenting #define VERBOSE_DEBUG.

While at it, visually detach the "return ret;" statement.

Use __func__ instead of explicitly hardcoding the function name. This, in
turn makes checkpatch issue this for the message in printer_close():

WARNING: Unnecessary ftrace-like logging - prefer using ftrace
54: FILE: drivers/usb/gadget/function/f_printer.c:387:
+	VDBG(dev, "%s\n", __func__);

which lets us eliminate the debug message from printer_close() altogether.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
---
Attention

This patch depends on a recent patch from Dan Carpenter:

usb: gadget: function: use after free in printer_close()

 drivers/usb/gadget/function/f_printer.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/gadget/function/f_printer.c b/drivers/usb/gadget/function/f_printer.c
index 01e842e1ba2f..d686c7be4fb5 100644
--- a/drivers/usb/gadget/function/f_printer.c
+++ b/drivers/usb/gadget/function/f_printer.c
@@ -11,6 +11,8 @@
  * Copyright (C) 2006 Craig W. Nadler
  */
 
+/* #define VERBOSE_DEBUG */
+
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/delay.h>
@@ -364,7 +366,8 @@ printer_open(struct inode *inode, struct file *fd)
 	spin_unlock_irqrestore(&dev->lock, flags);
 
 	kref_get(&dev->kref);
-	DBG(dev, "printer_open returned %x\n", ret);
+	VDBG(dev, "%s returned %x\n", __func__, ret);
+
 	return ret;
 }
 
@@ -381,7 +384,6 @@ printer_close(struct inode *inode, struct file *fd)
 	dev->printer_status &= ~PRINTER_SELECTED;
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	DBG(dev, "printer_close\n");
 	kref_put(&dev->kref, printer_dev_free);
 
 	return 0;
-- 
2.25.1