USB: ene_ub6250: fix memory leak in ene_load_bincode()

"buf" gets allocated twice in a row.  It's the second allocation which
is correct.  The first one should be removed.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Acked-by: huajun li <huajun.li.lee@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>