staging: pi433: prevent uninitialized data from being printed out

staging: pi433: prevent uninitialized data from being printed out

local_buffer is not initialised before data is passed to
spi_sync_transfer. In case spi* function fails then the dev_dbg
statement after that can potentially print out uninitialised data

this patch initialises local_buffer array.

Signed-off-by: Paulo Miguel Almeida <paulo.miguel.almeida.rodenas@gmail.com>
Link: https://lore.kernel.org/r/Yhmruyr2BUn0+3O3@mail.google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>