USB: EHCI: change toggle only upon successful reset

ehci-hcd uses a value of 0 in an endpoint's toggle flag to indicate
that the endpoint has been reset (and therefore the Data Toggle bit
needs to be cleared in the endpoint's QH overlay region).

The toggle flag should be set to 0 only when ehci_endpoint_reset()
succeeds.  This patch moves the usb_settoggle() call into the
appropriate branch of the "if" statement.

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