Bug fix for recommending zvol blocksize

This commit fixes an issue where we are not sending 'K' suffix with the recommended blocksize which we were doing before and this results in change in behavior with existing implementation in UI/middleware breaking.

src/middlewared/middlewared/plugins/pool.py

@@ -4040,7 +4040,7 @@ async def recommended_zvol_blocksize(self, pool):
             if disks > maxdisks:
                 maxdisks = disks
 
-        return f'{max(16, min(128, 2 ** ((maxdisks * 8) - 1).bit_length()))}'
+        return f'{max(16, min(128, 2 ** ((maxdisks * 8) - 1).bit_length()))}K'
 
     @item_method
     @accepts(Str('id', required=True))