usb: gadgetfs remove delayed init mode

Gadgetfs had a mode in which endpoint descriptors were written by the user
program before connection.  This mode had some bugs, and hasn't seen much
(if any) use.  This patch removes that mode, leaving the mode of operation
where the user program waits for endpoint 0 to report a SET_CONFIGURATION,
and only then configures the endpoints.

From: "Phil Endecott" <spam_from_usb_devel@chezphil.org>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>