messages/MClientCaps: init peer.flags

*** CID 1258789:  Uninitialized scalar field  (UNINIT_CTOR)
/messages/MClientCaps.h: 132 in MClientCaps::MClientCaps(int, inodeno_t,
inodeno_t, unsigned long, int, unsigned int)()
126         head.ino = ino;
127         head.realm = realm;
128         head.cap_id = id;
129         head.migrate_seq = mseq;
130         peer.cap_id = 0;
131         inline_version = 0;
>>>     CID 1258789:  Uninitialized scalar field  (UNINIT_CTOR)
>>>     Non-static class member field "peer.flags" is not initialized in this
constructor nor in any functions that it calls.
132       }
133     private:
134       ~MClientCaps() {}
135
136     public:
137       const char *get_type_name() const { return "Cfcap";}

Signed-off-by: Sage Weil <sage@redhat.com>