Fix compiler warnings and errors in ldb.c

Summary:
stdlib.h is needed for exit()
--readhead --> --readahead

Task ID: #

Blame Rev:

Test Plan:
compile

Revert Plan:

Database Impact:

Memcache Impact:

Other Notes:

EImportant:

- begin *PUBLIC* platform impact section -
Bugzilla: #
- end platform impact -
fix compiler warnings & errors

Reviewers: dhruba

Reviewed By: dhruba

CC: heyongqiang

Differential Revision: https://reviews.facebook.net/D5805

db/db_bench.cc

@@ -1190,7 +1190,7 @@ int main(int argc, char** argv) {
     } else if (sscanf(argv[i], "--mmap_read=%d%c", &n, &junk) == 1 &&
                (n == 0 || n == 1)) {
       useMmapRead = n;
-    } else if (sscanf(argv[i], "--readhead=%d%c", &n, &junk) == 1 &&
+    } else if (sscanf(argv[i], "--readahead=%d%c", &n, &junk) == 1 &&
                (n == 0 || n == 1)) {
       useFsReadAhead = n;
     } else if (sscanf(argv[i], "--statistics=%d%c", &n, &junk) == 1 &&

tools/ldb.cc

@@ -5,6 +5,7 @@
 #include <string>
 #include <iostream>
 #include <sstream>
+#include <stdlib.h>
 
 #include "leveldb/db.h"
 #include "leveldb/options.h"
@@ -122,7 +123,7 @@ static void dump_db(
     }
   }
 
-  fprintf(stdout, "Keys in range: %d\n", count);
+  fprintf(stdout, "Keys in range: %lld\n", (long long) count);
 
   // Clean up
   delete iter;