fs: remove vfs_ioctl export

vfs_ioctl() is no longer called by anything outside of fs/ioctl.c, so
remove the global symbol and export as it is not needed.

Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Link: https://lore.kernel.org/2025083038-carving-amuck-a4ae@gregkh


Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>