Remove unnecessary type casts

storage/innobase/os/os0file.cc

@@ -2,7 +2,7 @@
 
 Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved.
 Copyright (c) 2009, Percona Inc.
-Copyright (c) 2013, 2018, MariaDB Corporation.
+Copyright (c) 2013, 2019, MariaDB Corporation.
 
 Portions of this file contain modifications contributed and copyrighted
 by Percona Inc.. Those modifications are
@@ -1766,6 +1766,8 @@ LinuxAIOHandler::resubmit(Slot* slot)
 	slot->n_bytes = 0;
 	slot->io_already_done = false;
 
+	compile_time_assert(sizeof(off_t) >= sizeof(os_offset_t));
+
 	struct iocb*	iocb = &slot->control;
 
 	if (slot->type.is_read()) {
@@ -1775,7 +1777,7 @@ LinuxAIOHandler::resubmit(Slot* slot)
 			slot->file,
 			slot->ptr,
 			slot->len,
-			static_cast<off_t>(slot->offset));
+			slot->offset);
 	} else {
 
 		ut_a(slot->type.is_write());
@@ -1785,7 +1787,7 @@ LinuxAIOHandler::resubmit(Slot* slot)
 			slot->file,
 			slot->ptr,
 			slot->len,
-			static_cast<off_t>(slot->offset));
+			slot->offset);
 	}
 
 	iocb->data = slot;
@@ -6316,7 +6318,7 @@ AIO::reserve_slot(
 #ifdef _WIN32
 	slot->len      = static_cast<DWORD>(len);
 #else
-	slot->len      = static_cast<ulint>(len);
+	slot->len      = len;
 #endif /* _WIN32 */
 	slot->type     = type;
 	slot->buf      = static_cast<byte*>(buf);