Fix failed compaction_filter_example and add it into make all

Summary:
Simple patch as title
Closes https://github.com/facebook/rocksdb/pull/1512

Differential Revision: D4186994

Pulled By: siying

fbshipit-source-id: 880f9b8

examples/Makefile

@@ -10,7 +10,7 @@ endif
 	
 .PHONY: clean librocksdb
 
-all: simple_example column_families_example compact_files_example c_simple_example optimistic_transaction_example transaction_example
+all: simple_example column_families_example compact_files_example c_simple_example optimistic_transaction_example transaction_example compaction_filter_example
 
 simple_example: librocksdb simple_example.cc
 	$(CXX) $(CXXFLAGS) $@.cc -o$@ ../librocksdb.a -I../include -O2 -std=c++11 $(PLATFORM_LDFLAGS) $(PLATFORM_CXXFLAGS) $(EXEC_LDFLAGS)

examples/compaction_filter_example.cc

@@ -77,7 +77,7 @@ int main() {
   db->Merge(wopts, "3", "data3");
   db->CompactRange(rocksdb::CompactRangeOptions(), nullptr, nullptr);
   fprintf(stderr, "filter.count_ = %d\n", filter.count_);
-  assert(filter.count_ == 1);
+  assert(filter.count_ == 0);
   fprintf(stderr, "filter.merge_count_ = %d\n", filter.merge_count_);
-  assert(filter.merge_count_ == 5);
+  assert(filter.merge_count_ == 6);
 }