Fix invalid pointer dereference because we didn't NULL-initializer a var.
Fix invalid pointer dereference because we didn't NULL-initializer a var.

rbultje/c99-to-c89,rbultje/c99-to-c89,libav/c99-to-c89,mstorsjo/c99-to-c89,mstorsjo/c99-to-c89,libav/c99-to-c89