container_of: Update header inclusions

The commit 848dba781f19 ("container_of: remove container_of_safe()")
removed the code that uses err.h. Replace the inclusion by stddef.h
which provides offsetof() definition which is still in use.

Signed-off-by: Andy Shevchenko <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
1 file changed