staging: rtl8192u: Remove commented header.

This patch removes the commented header <linux/config.h>
as it is not used in modern linux systems.
Signed-off-by: Navya Sri Nizamkari <navyasri.tech@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8192u/ieee80211/ieee80211_tx.c

@@ -32,7 +32,6 @@
 ******************************************************************************/
 
 #include <linux/compiler.h>
-//#include <linux/config.h>
 #include <linux/errno.h>
 #include <linux/if_arp.h>
 #include <linux/in6.h>