memory: Have memory_region_init_rom_nomigrate() handler return a boolean

Following the example documented since commit e3fe3988 ("error:
Document Error API usage rules"), have memory_region_init_rom_nomigrate
return a boolean indicating whether an error is set or not.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Gavin Shan <gshan@redhat.com>
Message-Id: <20231120213301.24349-4-philmd@linaro.org>
[PMD: Only update 'readonly' field on success (Manos Pitsidianakis)]
Message-Id: <af352e7d-3346-4705-be77-6eed86858d18@linaro.org>

include/exec/memory.h

@@ -1498,8 +1498,10 @@ void memory_region_init_alias(MemoryRegion *mr,
  *        must be unique within any device
  * @size: size of the region.
  * @errp: pointer to Error*, to store an error if it happens.
+ *
+ * Return: true on success, else false setting @errp with error.
  */
-void memory_region_init_rom_nomigrate(MemoryRegion *mr,
+bool memory_region_init_rom_nomigrate(MemoryRegion *mr,
                                       Object *owner,
                                       const char *name,
                                       uint64_t size,

system/memory.c

@@ -1701,14 +1701,19 @@ void memory_region_init_alias(MemoryRegion *mr,
     mr->alias_offset = offset;
 }
 
-void memory_region_init_rom_nomigrate(MemoryRegion *mr,
+bool memory_region_init_rom_nomigrate(MemoryRegion *mr,
                                       Object *owner,
                                       const char *name,
                                       uint64_t size,
                                       Error **errp)
 {
-    memory_region_init_ram_flags_nomigrate(mr, owner, name, size, 0, errp);
+    if (!memory_region_init_ram_flags_nomigrate(mr, owner, name,
+                                                size, 0, errp)) {
+         return false;
+    }
     mr->readonly = true;
+
+    return true;
 }
 
 void memory_region_init_rom_device_nomigrate(MemoryRegion *mr,