Remove useless casts to (const void *)

Similar to commit 7f798aca1d, but I didn't think to look for "const"
as well.

src/backend/storage/buffer/bufmgr.c

@@ -4292,7 +4292,7 @@ DropRelationsAllBuffers(SMgrRelation *smgr_reln, int nlocators)
 			RelFileLocator locator;
 
 			locator = BufTagGetRelFileLocator(&bufHdr->tag);
-			rlocator = bsearch((const void *) &(locator),
+			rlocator = bsearch(&locator,
 							   locators, n, sizeof(RelFileLocator),
 							   rlocator_comparator);
 		}
@@ -4646,7 +4646,7 @@ FlushRelationsAllBuffers(SMgrRelation *smgrs, int nrels)
 			RelFileLocator rlocator;
 
 			rlocator = BufTagGetRelFileLocator(&bufHdr->tag);
-			srelent = bsearch((const void *) &(rlocator),
+			srelent = bsearch(&rlocator,
 							  srels, nrels, sizeof(SMgrSortArray),
 							  rlocator_comparator);
 		}

src/backend/storage/lmgr/lock.c

@@ -550,7 +550,7 @@ GetLockTagsMethodTable(const LOCKTAG *locktag)
 uint32
 LockTagHashCode(const LOCKTAG *locktag)
 {
-	return get_hash_value(LockMethodLockHash, (const void *) locktag);
+	return get_hash_value(LockMethodLockHash, locktag);
 }
 
 /*

src/bin/pg_dump/pg_backup_archiver.c

@@ -1822,7 +1822,7 @@ ahwrite(const void *ptr, size_t size, size_t nmemb, ArchiveHandle *AH)
 			size_t		avail = AH->lo_buf_size - AH->lo_buf_used;
 
 			memcpy((char *) AH->lo_buf + AH->lo_buf_used, ptr, avail);
-			ptr = (const void *) ((const char *) ptr + avail);
+			ptr = (const char *) ptr + avail;
 			remaining -= avail;
 			AH->lo_buf_used += avail;
 			dump_lo_buf(AH);

src/test/modules/test_tidstore/test_tidstore.c

@@ -292,13 +292,13 @@ check_set_block_offsets(PG_FUNCTION_ARGS)
 	qsort(items.lookup_tids, items.num_tids, sizeof(ItemPointerData), itemptr_cmp);
 	for (int i = 0; i < items.num_tids; i++)
 	{
-		if (itemptr_cmp((const void *) &items.insert_tids[i], (const void *) &items.iter_tids[i]) != 0)
+		if (itemptr_cmp(&items.insert_tids[i], &items.iter_tids[i]) != 0)
 			elog(ERROR, "TID iter array doesn't match verification array, got (%u,%u) expected (%u,%u)",
 				 ItemPointerGetBlockNumber(&items.iter_tids[i]),
 				 ItemPointerGetOffsetNumber(&items.iter_tids[i]),
 				 ItemPointerGetBlockNumber(&items.insert_tids[i]),
 				 ItemPointerGetOffsetNumber(&items.insert_tids[i]));
-		if (itemptr_cmp((const void *) &items.insert_tids[i], (const void *) &items.lookup_tids[i]) != 0)
+		if (itemptr_cmp(&items.insert_tids[i], &items.lookup_tids[i]) != 0)
 			elog(ERROR, "TID lookup array doesn't match verification array, got (%u,%u) expected (%u,%u)",
 				 ItemPointerGetBlockNumber(&items.lookup_tids[i]),
 				 ItemPointerGetOffsetNumber(&items.lookup_tids[i]),