[analyzer] Prevent crashing in NonNullParamChecker

https://bugs.llvm.org/show_bug.cgi?id=36381
rdar://37543426

Turns out, the type passed for the lambda capture was incorrect.
One more argument to abandon the getSVal overload which does not require the
type information.

Differential Revision: https://reviews.llvm.org/D43925

llvm-svn: 326520