Staging: rtl8192u: Replace memset with eth_zero_addr

Use eth_zero_addr to assign the zero address to the given address
array instead of memset when second argument is address of zero.
Note that the 6 in the third argument of memset appears to represent
an ethernet address size (ETH_ALEN).

The Coccinelle semantic patch that makes this change is as follows:

// <smpl>
@eth_zero_addr@
expression e;
@@

-memset(e,0x00,6);
+eth_zero_addr(e);
// </smpl>

Signed-off-by: Vaishali Thakkar <vthakkar1994@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>