net: lwm2m: cleanup memset usage during init

Several problems with memset usage in the LwM2M subsystem were
identified:
- Every single object that can have multiple instances is using
  memset to initialize static resource data during init.  This data
  will already be set to 0 because it is static, so the memset
  statements are unneeded.
- Instead of using memset during object init which is only called
  one time during kernel startup, let's add a memset to the
  object create function to ensure the resource data is cleared out.
  It could have been used prior and then released via a DELETE op.
- the IPSO Timer object was setting a lot of data structure members
  to 0 in the create function.  Let's do 1 memset on the entire
  structure and then only the non-zero values afterward.

Signed-off-by: Michael Scott <mike@foundries.io>
5 files changed