binderAllocationLimits: check remote binder null

Possible null de-ref hit one time?

This is not actually expected to fix this bug, but if it reproduces
again, it should give us slightly more information.

Change-Id: Ie3de2b50088179d1c7fcb8d492dfc092a2e45b91
Fixes: 291870594
Test: N/A
1 file changed