removed some unused things clang warned about

ft/fifo.cc

@@ -102,7 +102,6 @@ struct fifo {
     int   memory_used;  // How many bytes are in use?
 };
 
-const int fifo_initial_size = 4096;
 static void fifo_init(struct fifo *fifo) {
     fifo->n_items_in_fifo = 0;
     fifo->memory       = 0;

ft/ft-ops.cc

@@ -228,8 +228,6 @@ basement nodes, bulk fetch,  and partial fetch:
 
 #include <stdint.h>
 
-static const uint32_t this_version = FT_LAYOUT_VERSION;
-
 /* Status is intended for display to humans to help understand system behavior.
  * It does not need to be perfectly thread-safe.
  */
@@ -5853,14 +5851,6 @@ toku_ft_cursor_peek(FT_CURSOR cursor, const DBT **pkey, const DBT **pval)
     *pval = &cursor->val;
 }
 
-//We pass in toku_dbt_fake to the search functions, since it will not pass the
-//key(or val) to the heaviside function if key(or val) is NULL.
-//It is not used for anything else,
-//the actual 'extra' information for the heaviside function is inside the
-//wrapper.
-static const DBT __toku_dbt_fake = {};
-static const DBT* const toku_dbt_fake = &__toku_dbt_fake;
-
 bool toku_ft_cursor_uninitialized(FT_CURSOR c) {
     return ft_cursor_not_set(c);
 }

ft/quicklz.cc

@@ -311,6 +311,7 @@ static __inline void memcpy_up(unsigned char *dst, const unsigned char *src, ui3
 #endif
 }
 
+__attribute__((unused))
 static __inline void update_hash(qlz_state_decompress *state, const unsigned char *s)
 {
 #if QLZ_COMPRESSION_LEVEL == 1