staging: r8188eu: don't store nr_endpoint in a global struct

There's no need to store the number of endpoints in a global struct.
We only need it at startup when we iterate over the endpoints.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20211126173205.21352-8-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>