qa/valgrind.supp: suppress the ColumnFamily ctor called on init

qa/valgrind.supp: suppress the ColumnFamily ctor called on init

```
    <frame>
      <ip>0x1712F1E</ip>
      <obj>/home/rzarzynski/ceph3/build/bin/ceph-mon</obj>
      <fn>rocksdb::BytewiseComparator()</fn>
      <dir>/home/rzarzynski/ceph3/src/rocksdb/util</dir>
      <file>comparator.cc</file>
      <line>304</line>
    </frame>
    <frame>
      <ip>0x162361C</ip>
      <obj>/home/rzarzynski/ceph3/build/bin/ceph-mon</obj>
      <fn>rocksdb::ColumnFamilyOptions::ColumnFamilyOptions()</fn>
      <dir>/home/rzarzynski/ceph3/src/rocksdb/options</dir>
      <file>options.cc</file>
      <line>123</line>
    </frame>
    <frame>
      <ip>0x12CA21E</ip>
      <obj>/home/rzarzynski/ceph3/build/bin/ceph-mon</obj>
      <fn>Options</fn>
      <dir>/home/rzarzynski/ceph3/build/../src/rocksdb/include/rocksdb</dir>
      <file>options.h</file>
      <line>1409</line>
    </frame>
    <frame>
      <ip>0x12CA21E</ip>
      <obj>/home/rzarzynski/ceph3/build/bin/ceph-mon</obj>
      <fn>RocksDBStore::init(std::__cxx11::basic_string&lt;char, std::char_traits&lt;char&gt;, std::allocator&lt;char&gt; &gt;)</fn>
      <dir>/home/rzarzynski/ceph3/build/../src/kv</dir>
      <file>RocksDBStore.cc</file>
      <line>400</line>
    </frame>
```

Signed-off-by: Radoslaw Zarzynski <rzarzyns@redhat.com>