Revert "hw/sparc64/niagara: Use blk_name() instead of open-coding it"

This reverts commit 1881f33.

This commit breaks "-drive if=pflash,readonly=on,file=image.iso".  It
claims to merely replace an open-coded version of blk_name() by a
call, but that's not the case.  Sorry for the inconvenience!

Reported-by: Jakub Jermář <jakub@jermar.eu>
Cc: qemu-stable@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20230515151104.1350155-1-armbru@redhat.com>
Acked-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
(cherry picked from commit ac5e8c1)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

hw/sparc64/niagara.c

@@ -23,6 +23,7 @@
  */
 
 #include "qemu/osdep.h"
+#include "block/block_int-common.h"
 #include "qemu/units.h"
 #include "cpu.h"
 #include "hw/boards.h"
@@ -143,9 +144,10 @@ static void niagara_init(MachineState *machine)
             memory_region_add_subregion(get_system_memory(),
                                         NIAGARA_VDISK_BASE, &s->vdisk_ram);
             dinfo->is_default = 1;
-            rom_add_file_fixed(blk_name(blk), NIAGARA_VDISK_BASE, -1);
+            rom_add_file_fixed(blk_bs(blk)->filename, NIAGARA_VDISK_BASE, -1);
         } else {
-            error_report("could not load ram disk '%s'", blk_name(blk));
+            error_report("could not load ram disk '%s'",
+                         blk_bs(blk)->filename);
             exit(1);
         }
     }