qemu-img: Avoid qerror_report_err() outside QMP handlers, again

qerror_report_err() is a transitional interface to help with
converting existing monitor commands to QMP.  It should not be used
elsewhere.  Replace by error_report_err().

Commit 6936f299 cleaned that up in qemu-img.c, but two calls have crept
in since.  Take care of them the same way.
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NKevin Wolf <kwolf@redhat.com>

qemu-img.c

@@ -274,8 +274,7 @@ static int print_block_option_help(const char *filename, const char *fmt)
     if (filename) {
         proto_drv = bdrv_find_protocol(filename, true, &local_err);
         if (!proto_drv) {
-            qerror_report_err(local_err);
-            error_free(local_err);
+            error_report_err(local_err);
             qemu_opts_free(create_opts);
             return 1;
         }
@@ -1526,8 +1525,7 @@ static int img_convert(int argc, char **argv)
 
     proto_drv = bdrv_find_protocol(out_filename, true, &local_err);
     if (!proto_drv) {
-        qerror_report_err(local_err);
-        error_free(local_err);
+        error_report_err(local_err);
         ret = -1;
         goto out;
     }