Remove useless casts to (void *) in hash_search() calls

Some of these appear to be leftovers from when hash_search() took a
char * argument (changed in 5999e78fc4).

Since after this there is some more horizontal space available, do
some light reformatting where suitable.

Reviewed-by: Corey Huinker <corey.huinker@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/fd9adf5d-b1aa-e82f-e4c7-263c30145807%40enterprisedb.com

src/backend/storage/sync/sync.c

@@ -501,7 +501,7 @@ RememberSyncRequest(const FileTag *ftag, SyncRequestType type)
 
 		/* Cancel previously entered request */
 		entry = (PendingFsyncEntry *) hash_search(pendingOps,
-												  (void *) ftag,
+												  ftag,
 												  HASH_FIND,
 												  NULL);
 		if (entry != NULL)
@@ -557,7 +557,7 @@ RememberSyncRequest(const FileTag *ftag, SyncRequestType type)
 		Assert(type == SYNC_REQUEST);
 
 		entry = (PendingFsyncEntry *) hash_search(pendingOps,
-												  (void *) ftag,
+												  ftag,
 												  HASH_ENTER,
 												  &found);
 		/* if new entry, or was previously canceled, initialize it */