dib0700: protect the dib0700 buffer access

dib0700: protect the dib0700 buffer access

commit bff469f4167fdabfe15294f375577d7eadbaa1bb upstream.

This patch protects the common buffer access inside the dib0700 in order
to manage concurrent access. This protection is done using mutex.

Cc: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Florian Mickler <florian@mickler.org>
Signed-off-by: Javier Marcet <javier@marcet.info>
Signed-off-by: Olivier Grenie <olivier.grenie@dibcom.fr>
Signed-off-by: Patrick Boettcher <patrick.boettcher@dibcom.fr>
[mchehab@redhat.com: dprint requires 3 arguments. Replaced by dib_info]
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>