setup: drop repository_format_version global

Nobody reads this anymore, and they're not likely to; the
interesting thing is whether or not we passed
check_repository_format(), and possibly the individual
"extension" variables.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -747,7 +747,6 @@ extern int grafts_replace_parents;
  */
 #define GIT_REPO_VERSION 0
 #define GIT_REPO_VERSION_READ 1
-extern int repository_format_version;
 extern int repository_format_precious_objects;
 
 struct repository_format {

environment.c

@@ -25,7 +25,6 @@ int log_all_ref_updates = -1; /* unspecified */
 int warn_ambiguous_refs = 1;
 int warn_on_object_refname_ambiguity = 1;
 int ref_paranoia = -1;
-int repository_format_version;
 int repository_format_precious_objects;
 const char *git_commit_encoding;
 const char *git_log_output_encoding;

setup.c

@@ -428,7 +428,6 @@ static int check_repository_format_gently(const char *gitdir, int *nongit_ok)
 		die("%s", err.buf);
 	}
 
-	repository_format_version = candidate.version;
 	repository_format_precious_objects = candidate.precious_objects;
 	string_list_clear(&candidate.unknown_extensions, 0);
 	if (!has_common) {