Remove a couple of log statements.

These log statements have questionable value, and hinder the effort
of separating the high and low level DWARF parsing interfaces inside
of LLDB.  Removing them for now, and if/when we need such log statements
again in the future, we can add them back (if possible) or introduce a
mechanism for logging from the low-level interface in such a way that it
isn't coupled to the high level interface.

Differential Revision: https://reviews.llvm.org/D59498

llvm-svn: 356469