Add a null pointer check for wifi_chip in am: 4e634924 am: 26b62570 am:...

Add a null pointer check for wifi_chip in am: 4e634924 am: 26b62570 am: 590248f6 am: 38b17aec am: 4d0c1a01

Original change: https://android-review.googlesource.com/c/platform/hardware/interfaces/+/2279026



Change-Id: I6ae2b23ef9181e7f2bd3a074eb447550bb49b0fa
Signed-off-by: Automerger Merge Worker <android-build-automerger-merge-worker@system.gserviceaccount.com>