Remove the assertion as it was useless and broken.

Enforcing the assert caused the following tests to fail:
Clang :: Analysis__bstring.c
Clang :: Analysis__comparison-implicit-casts.cpp
Clang :: Analysis__malloc-interprocedural.c
Clang :: Analysis__malloc.c
Clang :: Analysis__redefined_system.c
Clang :: Analysis__string.c
Clang :: Analysis__weak-functions.c

llvm-svn: 235190