Commit 64252c75a removed the useless dget from dentry_unhash but didn't
fix up this caller in the usb code. There used to be exactly one dput per
dentry_unhash call; now there are none.
Tested-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>