vcs-svn: remove more unused prototypes and declarations

I forgot to remove these in v1.7.10-rc0~118^2~4^2~5^2~4 (vcs-svn:
eliminate repo_tree structure, 2010-12-10).

This finishes what was started in commit 36f63b50 (vcs-svn: remove
unused prototypes, 2017-08-21).

Signed-off-by: Jonathan Nieder <jrnieder@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

vcs-svn/repo_tree.h

@@ -1,14 +1,11 @@
 #ifndef REPO_TREE_H_
 #define REPO_TREE_H_
 
-struct strbuf;
-
 #define REPO_MODE_DIR 0040000
 #define REPO_MODE_BLB 0100644
 #define REPO_MODE_EXE 0100755
 #define REPO_MODE_LNK 0120000
 
-uint32_t next_blob_mark(void);
 void svn_repo_copy(uint32_t revision, const char *src, const char *dst);
 const char *svn_repo_read_path(const char *path, uint32_t *mode_out);
 void svn_repo_delete(const char *path);