staging: tidspbridge: replace strict_strtol() with kstrtos32()

The usage of strict_strtol() is not preferred, because
strict_strtol() is obsolete. Thus, kstrtos32() should be
used in order to convert a string to s32. Also, error handling
is added to get rid of a __must_check warning.

This fixes a memory corruption bug as well.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>