[uaccess] Remove redundant copy_from_user() and copy_to_user()

Remove the now-redundant copy_from_user() and copy_to_user() wrapper
functions.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/rtl818x/rtl818x.c

@@ -20,6 +20,7 @@
 FILE_LICENCE(GPL2_ONLY);
 
 #include <stdint.h>
+#include <string.h>
 #include <errno.h>
 #include <stdio.h>
 #include <unistd.h>