staging: rtl8192u: remove dead and commented-out code in r8192U_core.c

This cleanup patch removes commented-out code and
the functions rtl8192_dump_reg() and print_buffer()
which are not called anywhere in the driver.
Signed-off-by: Xenia Ragiadakou <burzalodowa@gmail.com>
Reviewed-by: Dan Carpenter<dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>