USB: EHCI: Refactor "if (handshake()) state = HC_STATE_HALT"

Refactor the EHCI "if (handshake()) state = HC_STATE_HALT" idiom,
which appears 4 times, by replacing it with calls to a new function
called handshake_on_error_set_halt().  Saves a few bytes too.

Signed-off-by: Karsten Wiese <fzu@wemgehoertderstaat.de>
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>