Follow-up to r29036: Now that the "mergeinfo" transaction file is no
longer being passed to sqlite, we don't need it to exist at all.
Remove all references to it.
* subversion/libsvn_fs_fs/fs.h
(PATH_TXN_MERGEINFO): Remove.
* subversion/libsvn_fs_fs/fs_fs.c
(path_txn_mergeinfo, get_txn_mergeinfo,
svn_fs_fs__change_txn_mergeinfo): Remove.
(commit_body): Don't call get_txn_mergeinfo.
* subversion/libsvn_fs_fs/structure
Remove all references to "mergeinfo" file.
git-svn-id: http://svn.collab.net/repos/svn/trunk@29114 612f8ebc-c883-4be0-9ee0-a4e9ef946e3a