most: core: use function subsys_initcall()

This patch replaces function module_init() with subsys_initcall().
It is needed to ensure that the core module of the driver is
initialized before a component tries to register with the core. This
leads to a NULL pointer dereference if the driver is configured as
in-tree.

Signed-off-by: Christian Gromm <[email protected]>
Reported-by: kernel test robot <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: cgro

drivers/most/core.c

@@ -1483,7 +1483,7 @@ static void __exit most_exit(void)
 	ida_destroy(&mdev_id);
 }
 
-module_init(most_init);
+subsys_initcall(most_init);
 module_exit(most_exit);
 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Christian Gromm <[email protected]>");