Gcc 7 ignored quantifiers

Summary:
The casting seemed to cause a problem.

I think this might increase it to unsigned long.
Closes https://github.com/facebook/rocksdb/pull/2562

Differential Revision: D5406842

Pulled By: siying

fbshipit-source-id: 736adef31448229a58a1a48bdbe77792f36736e8

table/block_based_table_builder.cc

@@ -80,10 +80,10 @@ FilterBlockBuilder* CreateFilterBlockBuilder(
       // until index builder actully cuts the partition, we take the lower bound
       // as partition size.
       assert(table_opt.block_size_deviation <= 100);
-      auto partition_size =
+      auto partition_size = static_cast<uint32_t>(
-          static_cast<const uint32_t>(table_opt.metadata_block_size *
+          table_opt.metadata_block_size *
           (100 - table_opt.block_size_deviation));
-      partition_size = std::max(partition_size, static_cast<const uint32_t>(1));
+      partition_size = std::max(partition_size, static_cast<uint32_t>(1));
       return new PartitionedFilterBlockBuilder(
           opt.prefix_extractor, table_opt.whole_key_filtering,
           filter_bits_builder, table_opt.index_block_restart_interval,

table/partitioned_filter_block_test.cc

@@ -92,10 +92,10 @@ class PartitionedFilterBlockTest : public testing::Test {
   PartitionedFilterBlockBuilder* NewBuilder(
       PartitionedIndexBuilder* const p_index_builder) {
     assert(table_options_.block_size_deviation <= 100);
-    auto partition_size = static_cast<const uint32_t>(
+    auto partition_size = static_cast<uint32_t>(
         table_options_.metadata_block_size *
-        (100 - table_options_.block_size_deviation));
+        ( 100 - table_options_.block_size_deviation));
-    partition_size = std::max(partition_size, static_cast<const uint32_t>(1));
+    partition_size = std::max(partition_size, static_cast<uint32_t>(1));
     return new PartitionedFilterBlockBuilder(
         nullptr, table_options_.whole_key_filtering,
         table_options_.filter_policy->GetFilterBitsBuilder(),