Staging: rtl8192e: Fix incorrect casting in rtllib_rx.c

This patch fixes the following sparse warning in rtllib_rx.c-

drivers/staging/rtl8192e/rtllib_rx.c:2267:34: warning: cast to restricted __le32
drivers/staging/rtl8192e/rtllib_rx.c:2268:34: warning: cast to restricted __le32
drivers/staging/rtl8192e/rtllib_rx.c:2269:36: warning: cast to restricted __le32
drivers/staging/rtl8192e/rtllib_rx.c:2269:36: warning: cast from restricted __le16

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>