object-store: rename and expand packed_git's sha1 member

This member is used to represent the pack checksum of the pack in
question.  Expand this member to be GIT_MAX_RAWSZ bytes in length so it
works with longer hashes and rename it to be "hash" instead of "sha1".
This transformation was made with a change to the definition and the
following semantic patch:

@@
struct packed_git *E1;
@@
- E1->sha1
+ E1->hash

@@
struct packed_git E1;
@@
- E1.sha1
+ E1.hash

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/packfile.c b/packfile.c
index 16bcb75..e6e8861 100644
--- a/packfile.c
+++ b/packfile.c
@@ -235,7 +235,7 @@ struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path)
 	struct packed_git *p = alloc_packed_git(alloc);
 
 	memcpy(p->pack_name, path, alloc); /* includes NUL */
-	hashcpy(p->sha1, sha1);
+	hashcpy(p->hash, sha1);
 	if (check_packed_git_idx(idx_path, p)) {
 		free(p);
 		return NULL;
@@ -722,8 +722,8 @@ struct packed_git *add_packed_git(const char *path, size_t path_len, int local)
 	p->pack_local = local;
 	p->mtime = st.st_mtime;
 	if (path_len < the_hash_algo->hexsz ||
-	    get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->sha1))
-		hashclr(p->sha1);
+	    get_sha1_hex(path + path_len - the_hash_algo->hexsz, p->hash))
+		hashclr(p->hash);
 	return p;
 }