*.[ch]: remove extern from function declarations using spatch

There has been a push to remove extern from function declarations.
Remove some instances of "extern" for function declarations which are
caught by Coccinelle. Note that Coccinelle has some difficulty with
processing functions with `__attribute__` or varargs so some `extern`
declarations are left behind to be dealt with in a future patch.

This was the Coccinelle patch used:

	@@
	type T;
	identifier f;
	@@
	- extern
	  T f(...);

and it was run with:

	$ git ls-files \*.{c,h} |
		grep -v ^compat/ |
		xargs spatch --sp-file contrib/coccinelle/noextern.cocci --in-place

Files under `compat/` are intentionally excluded as some are directly
copied from external sources and we should avoid churning them as much
as possible.

Signed-off-by: Denton Liu <liu.denton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/remote.h b/remote.h
index da53ad5..7b1eed6 100644
--- a/remote.h
+++ b/remote.h
@@ -119,13 +119,13 @@ struct ref {
 #define REF_HEADS	(1u << 1)
 #define REF_TAGS	(1u << 2)
 
-extern struct ref *find_ref_by_name(const struct ref *list, const char *name);
+struct ref *find_ref_by_name(const struct ref *list, const char *name);
 
 struct ref *alloc_ref(const char *name);
 struct ref *copy_ref(const struct ref *ref);
 struct ref *copy_ref_list(const struct ref *ref);
 void sort_ref_list(struct ref **, int (*cmp)(const void *, const void *));
-extern int count_refspec_match(const char *, struct ref *refs, struct ref **matched_ref);
+int count_refspec_match(const char *, struct ref *refs, struct ref **matched_ref);
 int ref_compare_name(const void *, const void *);
 
 int check_ref_type(const struct ref *ref, int flags);
@@ -139,13 +139,13 @@ struct oid_array;
 struct packet_reader;
 struct argv_array;
 struct string_list;
-extern struct ref **get_remote_heads(struct packet_reader *reader,
+struct ref **get_remote_heads(struct packet_reader *reader,
 				     struct ref **list, unsigned int flags,
 				     struct oid_array *extra_have,
 				     struct oid_array *shallow_points);
 
 /* Used for protocol v2 in order to retrieve refs from a remote */
-extern struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
+struct ref **get_remote_refs(int fd_out, struct packet_reader *reader,
 				    struct ref **list, int for_push,
 				    const struct argv_array *ref_prefixes,
 				    const struct string_list *server_options);
@@ -287,9 +287,9 @@ struct push_cas_option {
 	int alloc;
 };
 
-extern int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
+int parseopt_push_cas_option(const struct option *, const char *arg, int unset);
 
-extern int is_empty_cas(const struct push_cas_option *);
+int is_empty_cas(const struct push_cas_option *);
 void apply_push_cas(struct push_cas_option *, struct remote *, struct ref *);
 
 #endif