odb: drop whence field from object info

In the preceding commits we have migrated all callers to derive their
information of how a specific object is stored to use the new object
info source instead, and hence the field is now unused. Drop it.

Signed-off-by: Patrick Steinhardt <ps@pks.im>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

odb.c

@@ -691,7 +691,6 @@ static int oid_object_info_convert(struct repository *r,
 			return -1;
 		}
 	}
-	input_oi->whence = new_oi.whence;
 	if (input_oi->sourcep)
 		*input_oi->sourcep = *new_oi.sourcep;
 	return ret;

odb.h

@@ -311,13 +311,6 @@ struct object_info {
 	 * or multiple times in the same source.
 	 */
 	struct object_info_source *sourcep;
-
-	/* Response */
-	enum {
-		OI_CACHED,
-		OI_LOOSE,
-		OI_PACKED,
-	} whence;
 };
 
 /*

odb/source-inmemory.c

@@ -54,8 +54,6 @@ static void populate_object_info(struct odb_source_inmemory *source,
 		*oi->mtimep = 0;
 	if (oi->sourcep)
 		oi->sourcep->source = &source->base;
-
-	oi->whence = OI_CACHED;
 }
 
 static int odb_source_inmemory_read_object_info(struct odb_source *source,

odb/source-loose.c

@@ -198,8 +198,6 @@ out:
 			oidclr(oi->delta_base_oid, loose->base.odb->repo->hash_algo);
 		if (oi->sourcep && !ret)
 			oi->sourcep->source = &loose->base;
-		if (!ret)
-			oi->whence = OI_LOOSE;
 	}
 
 	return ret;

packfile.c

@@ -1421,8 +1421,6 @@ int packed_object_info_with_index_pos(struct odb_source_packed *source,
 			oidclr(oi->delta_base_oid, p->repo->hash_algo);
 	}
 
-	oi->whence = OI_PACKED;
-
 	if (oi->sourcep) {
 		if (!source)
 			BUG("cannot request source without an owning source");