misc: fs_loader: Initialize actread variable

misc: fs_loader: Initialize actread variable

Initialize the actread variable to prevent undefined behavior
that can occur if the variable is used before being assigned a
value.

This will help to prevent potential issues, especially if
actread is used (e.g., read, incremented, or returned) before
being explicitly set elsewhere in the code.

Signed-off-by: Alif Zakuan Yuslaimi <alif.zakuan.yuslaimi@altera.com>