usbcore: compare and release one bos descriptor in usb_reset_and_verify_device()

In usb_reset_and_verify_device(), hub_port_init() allocates a new bos
descriptor to hold the value read by the device. The new bos descriptor
has to be compared with the old one in order to figure out if device 's
firmware has changed in which case the device has to be reenumerated.
In the original code, none of the two descriptors was deallocated leading
to memory leaks.

This patch compares the old bos descriptor with the new one to detect change
in firmware and releases the newly allocated bos descriptor to prevent memory
leak.

Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reported-by: Martin MOKREJS <mmokrejs@gmail.com>
Tested-by: Martin MOKREJS <mmokrejs@gmail.com>
Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>