Fix log spam when MonoPipe is unable to get local frequency

Local frequency does not change, so only ask for it the first time a
MonoPipe is constructed in a given client process.  Thereafter use a
previously cached value.  Likewise, if the local frequency is unavailable,
only log this the first time.

Change-Id: Ib1fc7251c3832e02fe03811db39a87e500f1df50