Fix typo in Makefile.

git-svn-id: https://leveldb.googlecode.com/svn/trunk@4 62dab493-f737-651d-591e-8d6aee1b9529

Makefile

@@ -17,7 +17,7 @@ LIBOBJECTS = \
 	./db/db_impl.o \
 	./db/db_iter.o \
 	./db/filename.o \
-	./db/format.o \
+	./db/dbformat.o \
 	./db/log_reader.o \
 	./db/log_writer.o \
 	./db/memtable.o \