The usage of BUG() macro is generally discouraged in kernel, unless
it's a problem that results in a physical damage or loss of data.
This patch removes unnecessary BUG() macros and replaces the rest
with warning.
Signed-off-by: Bitan Biswas <bbiswas@nvidia.com> Reviewed-by: Dmitry Osipenko <digetx@gmail.com> Tested-by: Dmitry Osipenko <digetx@gmail.com> Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Wolfram Sang <wsa@the-dreams.de>