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, 2 insertions, 2 deletions

diff --git a/daemon/du.c b/daemon/du.c
index e6df2452..942a699a 100644
--- a/daemon/du.c
+++ b/daemon/du.c
@@ -46,7 +46,7 @@ do_du (const char *path)
   r = command (&out, &err, "du", "-s", buf, NULL);
   free (buf);
   if (r == -1) {
-    reply_with_error ("du: %s: %s", path, err);
+    reply_with_error ("%s: %s", path, err);
     free (out);
     free (err);
     return -1;
@@ -55,7 +55,7 @@ do_du (const char *path)
   free (err);
 
   if (sscanf (out, "%"SCNi64, &rv) != 1) {
-    reply_with_error ("du: %s: could not read output: %s", path, out);
+    reply_with_error ("%s: could not read output: %s", path, out);
     free (out);
     return -1;
   }