USB: Remove unneeded void * casts in core files

The patch removes unneeded casts for the following (void *) pointers:
 - struct file: private
 - struct urb: context
 - struct usb_bus: hcpriv
 - return value of kmalloc()

The patch also contains some whitespace cleanup in the relevant areas.

Signed-off-by: Tobias Klauser <tklauser@distanz.ch>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/usb/core/devices.c b/drivers/usb/core/devices.c
index 241d373..3538c2f 100644
--- a/drivers/usb/core/devices.c
+++ b/drivers/usb/core/devices.c
@@ -593,7 +593,7 @@
 /* Kernel lock for "lastev" protection */
 static unsigned int usb_device_poll(struct file *file, struct poll_table_struct *wait)
 {
-	struct usb_device_status *st = (struct usb_device_status *)file->private_data;
+	struct usb_device_status *st = file->private_data;
 	unsigned int mask = 0;
 
 	lock_kernel();
@@ -603,7 +603,7 @@
 			unlock_kernel();
 			return POLLIN;
 		}
-		
+
 		/* we may have dropped BKL - need to check for having lost the race */
 		if (file->private_data) {
 			kfree(st);