ehci: remove ehci_vdbg() verbose debugging statements

This patch removes ehci_vdbg debugging statements from EHCI host controller
driver because they produce too much information, lowering the signal to noise
ratio when debugging, and because they are not used anymore.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>