In commit 49e2c8f0 (MDEV-25743)
some more use of the printf-style format "%.*s" was added.
The length parameter is of type int, not size_t.
On 64-bit platforms that follow the LLP64 convention (such as
64-bit Microsoft Windows), sizeof(int)==4 and sizeof(size_t)==8.

Let us explicitly cast the lengths to the correct type in order
to avoid any trouble.