Revert "usb: host: ehci-sh: propagate errors from platform_get_irq()"

This reverts commit 1aebf115 as the
prerequsite commit for it is not in the tree.

Cc: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Sergey Shtylyov <s.shtylyov@omp.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>