USB: Remove BKL from lseek implementations

Replace it by
mutex_lock(&file->f_dentry->d_inode->i_mutex);
following the example of the generic method
Signed-off-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/core/devices.c

@@ -675,7 +675,7 @@ static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig)
 {
 	loff_t ret;
 
-	lock_kernel();
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
 
 	switch (orig) {
 	case 0:
@@ -691,7 +691,7 @@ static loff_t usb_device_lseek(struct file *file, loff_t offset, int orig)
 		ret = -EINVAL;
 	}
 
-	unlock_kernel();
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
 	return ret;
 }
 

drivers/usb/core/devio.c

@@ -122,7 +122,7 @@ static loff_t usbdev_lseek(struct file *file, loff_t offset, int orig)
 {
 	loff_t ret;
 
-	lock_kernel();
+	mutex_lock(&file->f_dentry->d_inode->i_mutex);
 
 	switch (orig) {
 	case 0:
@@ -138,7 +138,7 @@ static loff_t usbdev_lseek(struct file *file, loff_t offset, int orig)
 		ret = -EINVAL;
 	}
 
-	unlock_kernel();
+	mutex_unlock(&file->f_dentry->d_inode->i_mutex);
 	return ret;
 }