libutil: don't report DecompressionStream shutdown errors

we already report errors that happen during reads via exceptions
rethrown from read. reporting errors during destruction too is a
source of confusion for users since these errors are not usually
relevant and just the decompressor thread reporting short reads.
shorts reads during shutdown are not an error, they're expected.

fixes #1138

Change-Id: I7983ef0ed7722460f1d683bc8171a454b3d06e90

lix/libutil/compression.cc

@@ -369,7 +369,6 @@ struct DecompressionStream : DecompressorPipes, AsyncInputStream
             try {
                 thread.get();
             } catch (...) {
-                ignoreExceptionInDestructor();
             }
         }
     }