Shell history file accesses should capture errno earlier

In this code

std::stringstream ss;

ss << "Unable to " << what << " file " << filename << ": " << mongo::errnoWithDescription();

errno is captured too late — it may have been reset by the stringstream by the time errnoWithDescription() uses it.

There are also a few places where closing the file in response to an error, clobbers the actual errno of interest.