(ITS#7125) Misplaced connection_done() calls

[h.b.furuseth@usit.uio.no]

Full_Name: Hallvard B Furuseth
Version: 2.4.26 - 2.4.28
OS: Linux x86_64
URL: 
Submission from: (NULL) (129.240.203.186)
Submitted by: hallvard


Connection.c_mutex gets unlocked twice since since commit
9e00b6cc6ce2857490b33218bdaf1339319c5f60 (Add strictrefresh syncrepl
option): connection_done() is called inside connection_<first/next>()
loops, but connection_next() does the same inlined.

The functions should be used as:
        for (c=connection_first(...); c; c=connection_next(c,...)) {...}
        connection_done(c);
though connection_done(c) is currently unnecessary when c==NULL.

Fixing.