LP:782431 - active locks in released memory

Found during MariaDB tests with application verifier:

xt_ind_exit() frees memory block pointed to by ind_cac_globals.cg_blocks, but does not free page locks in it, that are initialized using XT_IPAGE_INIT_LOCK(self, &block->cb_lock) in xt_ind_init().

This makes application verifier unhappy on 64 bit Windows.

XTIndBlockPtr block = ind_cac_globals.cg_blocks;
for (u_int i=0; i<ind_cac_globals.cg_block_count; i++)

{ XT_IPAGE_FREE_LOCK(self, &block->cb_lock); block++; }