msm: net: ecm: add debug printings and remove of unneeded condition check

Add more printings to catch dangling references.
The condition that was removed is unnecessary because the validity check
before cover this (because that pointer is allocated with the netdev).

Change-Id: I439e148a0e6710a505297956b104a0b27fcf6ccf
Signed-off-by: Talel Atias <tatias@codeaurora.org>