sha1_file.c: remove unused function

has_pack_file() is not used anywhere.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

cache.h

@@ -683,7 +683,6 @@ extern int has_sha1_pack(const unsigned char *sha1);
 extern int has_sha1_file(const unsigned char *sha1);
 extern int has_loose_object_nonlocal(const unsigned char *sha1);
 
-extern int has_pack_file(const unsigned char *sha1);
 extern int has_pack_index(const unsigned char *sha1);
 
 extern const signed char hexval_table[256];

sha1_file.c

@@ -2458,14 +2458,6 @@ int has_pack_index(const unsigned char *sha1)
 	return 1;
 }
 
-int has_pack_file(const unsigned char *sha1)
-{
-	struct stat st;
-	if (stat(sha1_pack_name(sha1), &st))
-		return 0;
-	return 1;
-}
-
 int has_sha1_pack(const unsigned char *sha1)
 {
 	struct pack_entry e;