archive: declare struct archiver where it's needed

Move the declaration of struct archiver to archive.c, as this is the only
file left where it is used.

Signed-off-by: Rene Scharfe <rene.scharfe@lsrfire.ath.cx>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

archive.c

@@ -9,7 +9,11 @@ static const char archive_usage[] = \
 
 #define USES_ZLIB_COMPRESSION 1
 
-const struct archiver archivers[] = {
+const struct archiver {
+	const char *name;
+	write_archive_fn_t write_archive;
+	unsigned int flags;
+} archivers[] = {
 	{ "tar", write_tar_archive },
 	{ "zip", write_zip_archive, USES_ZLIB_COMPRESSION },
 };

archive.h

@@ -17,12 +17,6 @@ typedef int (*write_archive_fn_t)(struct archiver_args *);
 
 typedef int (*write_archive_entry_fn_t)(struct archiver_args *args, const unsigned char *sha1, const char *path, size_t pathlen, unsigned int mode, void *buffer, unsigned long size);
 
-struct archiver {
-	const char *name;
-	write_archive_fn_t write_archive;
-	unsigned int flags;
-};
-
 /*
  * Archive-format specific backends.
  */