ARM: OMAP: USB: Fixup ehci_hcd_omap_probe error path

A recent commit, [PATCH] Fix OMAP EHCI suspend/resume failure
(i693) '354ab856' causes ehci probe to fail on omap3xxx. This
exposed bugs in the ehci_hcd_omap_probe error path causing
an oops.

On the error path, call usb_remove_hcd if usb_add_hcd has been
called, and call usb_put_hcd if usb_alloc_hcd has been called.

Tested on BB-xM.

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