blockdev: Make -drive format=help print to stdout

Command line help explicitly requested by the user should be printed
to stdout, not stderr.  We do elsewhere.  Adjust -drive to match: use
qemu_printf() instead of error_printf().  Plain printf() would be
wrong because we need to print to the current monitor for "drive_add
... format=help".

Cc: Kevin Wolf <kwolf@redhat.com>
Cc: Max Reitz <mreitz@redhat.com>
Cc: qemu-block@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190417190641.26814-13-armbru@redhat.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/blockdev.c b/blockdev.c
index 4775a07..79fbac8 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -40,6 +40,7 @@
 #include "monitor/monitor.h"
 #include "qemu/error-report.h"
 #include "qemu/option.h"
+#include "qemu/qemu-print.h"
 #include "qemu/config-file.h"
 #include "qapi/qapi-commands-block.h"
 #include "qapi/qapi-commands-transaction.h"
@@ -301,7 +302,7 @@ DriveInfo *drive_get_next(BlockInterfaceType type)
 
 static void bdrv_format_print(void *opaque, const char *name)
 {
-    error_printf(" %s", name);
+    qemu_printf(" %s", name);
 }
 
 typedef struct {
@@ -530,11 +531,11 @@ static BlockBackend *blockdev_init(const char *file, QDict *bs_opts,
 
     if ((buf = qemu_opt_get(opts, "format")) != NULL) {
         if (is_help_option(buf)) {
-            error_printf("Supported formats:");
+            qemu_printf("Supported formats:");
             bdrv_iterate_format(bdrv_format_print, NULL, false);
-            error_printf("\nSupported formats (read-only):");
+            qemu_printf("\nSupported formats (read-only):");
             bdrv_iterate_format(bdrv_format_print, NULL, true);
-            error_printf("\n");
+            qemu_printf("\n");
             goto early_err;
         }