lpd.buf is non-const and discards the const qualifier of zerobuffer.
This fixes -Wdiscarded-qualifiers observed with a variety of compilers, including GCC 5.2.
Note that this does not change the type of zerobuffer, and merely makes the intent explicit.
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>