mds: init in cap_reconnect_t ctor

mds: init in cap_reconnect_t ctor

At (2): Non-static class member field "capinfo.cap_id" is not initialized in this constructor nor in any functions that it calls.
At (4): Non-static class member field "capinfo.wanted" is not initialized in this constructor nor in any functions that it calls.
At (6): Non-static class member field "capinfo.issued" is not initialized in this constructor nor in any functions that it calls.
At (8): Non-static class member field "capinfo.snaprealm" is not initialized in this constructor nor in any functions that it calls.
At (10): Non-static class member field "capinfo.pathbase" is not initialized in this constructor nor in any functions that it calls.
CID 717257 (#1 of 1): Uninitialized scalar field (UNINIT_CTOR)
At (12): Non-static class member field "capinfo.flock_len" is not initialized in this constructor nor in any functions that it calls.

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