[ASAN] Remove asserts introduced in https://reviews.llvm.org/D136197

Additional calls were introduced for outlining (opposite of inlining)
in https://reviews.llvm.org/D136197 which contain asserts that partial
poisoning of a single byte wouldn't happen consecutively but this is
too strong and actually does occur in Windows. Removing those asserts
as they are unnecessary

Differential Revision: https://reviews.llvm.org/D136645