Description of problem:
Glusterd crashes when peer probe is issued for an unresolvable hostname.

Version-Release number of selected component (if applicable):
mainline

Steps to Reproduce:
1. start glusterd in debug mode, "glusterd -LDEBUG"
2. gluster peer probe abcd, ctrl-c end before completion
3. gluster peer probe abcd, allow till completion
4. any gluster cli command
  
Actual results:
Glusterd will be crashed.

Expected results:
Glusterd shouldn't crash

Additional info:
Backtrace from coredump,
#0  0x00007f5531ec9e51 in __strlen_sse2 () from /lib/libc.so.6
#1  0x00007f5531f5a01e in xdr_string () from /lib/libc.so.6
#2  0x00007f55326177d4 in xdr_gf1_cli_probe_rsp (xdrs=0x7fffc517a380, 
    objp=0x7fffc517a460) at cli1-xdr.c:271
#3  0x00007f5531f5aa85 in xdr_sizeof () from /lib/libc.so.6
#4  0x00007f552fab7cac in glusterd_serialize_reply (req=0x7f552f17402c, 
    arg=0x7fffc517a460, outmsg=0x7fffc517a400, 
    xdrproc=0x7f5532617720 <xdr_gf1_cli_probe_rsp>) at glusterd-utils.c:408
#5  0x00007f552fab7e05 in glusterd_submit_reply (req=0x7f552f17402c, 
    arg=<optimized out>, payload=0x0, payloadcount=0, iobref=0x91f830, 
    xdrproc=<optimized out>) at glusterd-utils.c:463
#6  0x00007f552faaa2aa in glusterd_xfer_cli_probe_resp (req=0x7f552f17402c, op_ret=-1, 
    op_errno=107, 
    hostname=0x617254203a647265 <Address 0x617254203a647265 out of bounds>, 
    port=1953067886) at glusterd-handler.c:2312
#7  0x00007f552faabc7f in glusterd_friend_remove_notify (peerinfo=0x91f830, 
    req=0x7f552f17402c) at glusterd-handler.c:2669
#8  0x00007f552faac010 in glusterd_peer_rpc_notify (rpc=<optimized out>, 
    mydata=0x91fe30, event=<optimized out>, data=<optimized out>)
    at glusterd-handler.c:2755
#9  0x00007f5532830657 in rpc_clnt_notify (trans=<optimized out>, mydata=0x91ef40, 
    event=<optimized out>, data=<optimized out>) at rpc-clnt.c:879
#10 0x00007f553282c737 in rpc_transport_notify (this=<optimized out>, 
    event=<optimized out>, data=<optimized out>) at rpc-transport.c:498
#11 0x00007f552ef6bf65 in socket_connect_finish (this=0x91f1d0) at socket.c:1750
#12 0x00007f552ef6c228 in socket_event_handler (fd=<optimized out>, idx=2, 
    data=0x91f1d0, poll_in=1, poll_out=4, poll_err=<optimized out>) at socket.c:1782
#13 0x00007f5532a71c37 in event_dispatch_epoll_handler (i=<optimized out>, 
    events=0x91c380, event_pool=0x911500) at event.c:794
#14 event_dispatch_epoll (event_pool=0x911500) at event.c:856
#15 0x0000000000404546 in main (argc=<optimized out>, argv=0x7fffc517a7e8)
    at glusterfsd.c:1601

This bug is similar to bug-770048 but may or may not be related.