Remove this memory event, as clear() is called after loop, which will call the destructor of each item. Picked up by AddressSanitizer as this was attempting to free() memory allocated with new()

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10108 387891d4-d844-0410-90c0-e4c51a9137d3
AddressSanitizer: alloc-dealloc-mismatch (operator new vs free) in hud_close()

git-svn-id: svn://svn.icculus.org/fs2open/trunk/fs2_open@10109 387891d4-d844-0410-90c0-e4c51a9137d3