qemu-img: Call error_set_progname

Call error_set_progname during the qemu-img initialization, so that error
messages printed with error_report() use the right prefix.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
diff --git a/qemu-img.c b/qemu-img.c
index 1d936ed..f576cfb 100644
--- a/qemu-img.c
+++ b/qemu-img.c
@@ -23,6 +23,7 @@
  */
 #include "qemu-common.h"
 #include "qemu-option.h"
+#include "qemu-error.h"
 #include "osdep.h"
 #include "sysemu.h"
 #include "block_int.h"
@@ -1612,6 +1613,8 @@
     const img_cmd_t *cmd;
     const char *cmdname;
 
+    error_set_progname(argv[0]);
+
     bdrv_init();
     if (argc < 2)
         help();