x86/bugs: Use sysfs_emit()

commit 1d30800c0c0ae1d086ffad2bdf0ba4403370f132 upstream.

Those mitigations are very talkative; use the printing helper which pays
attention to the buffer size.

Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lore.kernel.org/r/20220809153419.10182-1-bp@alien8.de


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>