net/bnxt: cleanup and refactor session management

The return value of some functions is explicitly ignored
in cases where scope id may not be valid for internal EM
entries.
Additional minor refactoring and cleanups
- Change log level for some log messages to DEBUG instead of ERR.
- Check data size conformity and log appropriate message.

Signed-off-by: Michael Wildt <michael.wildt@broadcom.com>
Signed-off-by: Kishore Padmanabha <kishore.padmanabha@broadcom.com>
Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Reviewed-by: Randy Schacher <stuart.schacher@broadcom.com>
Reviewed-by: Ajit Khaparde <ajit.khaparde@broadcom.com>