Move core_partial_clone_filter_default to promisor-remote.c

Now that we can have a different default partial clone filter for
each promisor remote, let's hide core_partial_clone_filter_default
as a static in promisor-remote.c to avoid it being use for
anything other than managing backward compatibility.

Signed-off-by: Christian Couder <chriscool@tuxfamily.org>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

cache.h

@@ -961,7 +961,6 @@ extern int grafts_replace_parents;
 #define GIT_REPO_VERSION 0
 #define GIT_REPO_VERSION_READ 1
 extern int repository_format_precious_objects;
-extern const char *core_partial_clone_filter_default;
 extern int repository_format_worktree_config;
 
 /*

config.c

@@ -1344,11 +1344,6 @@ static int git_default_core_config(const char *var, const char *value, void *cb)
 		return 0;
 	}
 
-	if (!strcmp(var, "core.partialclonefilter")) {
-		return git_config_string(&core_partial_clone_filter_default,
-					 var, value);
-	}
-
 	if (!strcmp(var, "core.usereplacerefs")) {
 		read_replace_refs = git_config_bool(var, value);
 		return 0;

environment.c

@@ -31,7 +31,6 @@ int warn_ambiguous_refs = 1;
 int warn_on_object_refname_ambiguity = 1;
 int ref_paranoia = -1;
 int repository_format_precious_objects;
-const char *core_partial_clone_filter_default;
 int repository_format_worktree_config;
 const char *git_commit_encoding;
 const char *git_log_output_encoding;

promisor-remote.c

@@ -5,6 +5,7 @@
 #include "transport.h"
 
 static char *repository_format_partial_clone;
+static const char *core_partial_clone_filter_default;
 
 void set_repository_format_partial_clone(char *partial_clone)
 {
@@ -103,6 +104,10 @@ static int promisor_remote_config(const char *var, const char *value, void *data
 	int namelen;
 	const char *subkey;
 
+	if (!strcmp(var, "core.partialclonefilter"))
+		return git_config_string(&core_partial_clone_filter_default,
+					 var, value);
+
 	if (parse_config_key(var, "remote", &name, &namelen, &subkey) < 0)
 		return 0;