s390/zcrypt: Fix warning about wrong kernel doc comment

Fix this warning:
  Warning: drivers/s390/crypto/zcrypt_msgtype6.c:1253 This comment
  starts with '/**', but isn't a kernel-doc comment. Refer to
  Documentation/doc-guide/kernel-doc.rst

Reported-by: kernel test robot <[email protected]>
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/
Signed-off-by: Harald Freudenberger <[email protected]>
Reviewed-by: Holger Dengler <[email protected]>
Signed-off-by: Vasily Gorbik <[email protected]>

Author: hfreude

drivers/s390/crypto/zcrypt_msgtype6.c

@@ -1254,7 +1254,7 @@ static long zcrypt_msgtype6_send_ep11_cprb(bool userspace, struct zcrypt_queue *
 	return rc;
 }
 
-/**
+/*
  * Prepare a type6 CPRB message for random number generation
  *
  * @ap_dev: AP device pointer