pack: move pack-closing functions

The function close_pack_fd() needs to be temporarily made global. Its
scope will be restored to static in a subsequent commit.

Signed-off-by: Jonathan Tan <jonathantanmy@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/receive-pack.c

@@ -23,6 +23,7 @@
 #include "fsck.h"
 #include "tmp-objdir.h"
 #include "oidset.h"
+#include "packfile.h"
 
 static const char * const receive_pack_usage[] = {
 	N_("git receive-pack <git-dir>"),