daemon: Don't need to prefix error messages with the command name.

The RPC stubs already prefix the command name to error messages.
The daemon doesn't have to do this.  As a (small) benefit this also
makes the daemon slightly smaller.

Code in the daemon such as:

  if (argv[0] == NULL) {
    reply_with_error ("passed an empty list");
    return NULL;
  }

now results in error messages like this:

  ><fs> command ""
  libguestfs: error: command: passed an empty list

(whereas previously you would have seen ..command: command:..)

1 files changed, 1 insertions, 1 deletions

diff --git a/daemon/cmp.c b/daemon/cmp.c
index 2b7e33b5..bbf9c746 100644
--- a/daemon/cmp.c
+++ b/daemon/cmp.c
@@ -53,7 +53,7 @@ do_equal (const char *file1, const char *file2)
   free (file2buf);
 
   if (r == -1 || r > 1) {
-    reply_with_error ("cmp: %s", err);
+    reply_with_error ("%s", err);
     free (err);
     return -1;
   }