staging: rtl8192u: remove unnecessary function implementation

staging: rtl8192u: remove unnecessary function implementation

This driver is a single standalone driver and does not have any loading
dependencies on another associated drivers. The build results in one
single .ko object. The current implementation of the function
ieee80211_tkip_null simply returns back to the caller without any useful
instruction executions. It does not lead to auto-loading of any other
associated modules as the initial design implementation appears to be.

Hence the call to ieee80211_tkip_null() and its implementation is
unnecessary and should be removed.

Signed-off-by: Deepak R Varma <drv@mailo.com>
Link: https://lore.kernel.org/r/6f5a4313fc21365bf733c25385aef79554ffb253.1667237959.git.drv@mailo.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>