Clean up possible null dereference warning.

Added a runtime check for the value of the pointer.

(cherry picked from commit 88a69ded)

Bug: b/27101951
Test: verified warnings are gone.
Merged-In: Ia1004ca6fdc0937450a72d680c02a79aab22a739
Change-Id: Ia1004ca6fdc0937450a72d680c02a79aab22a739