staging: rtl8723bs: core: rtw_security: Demote non-conformant kernel-doc header

Fixes the following W=1 kernel build warning(s):

 from drivers/staging/rtl8188eu/core/rtw_security.c:10:
 drivers/staging/rtl8188eu/core/rtw_security.c:478: warning: Function parameter or member 'p1k' not described in 'phase1'
 drivers/staging/rtl8188eu/core/rtw_security.c:478: warning: Function parameter or member 'tk' not described in 'phase1'
 drivers/staging/rtl8188eu/core/rtw_security.c:478: warning: Function parameter or member 'ta' not described in 'phase1'
 drivers/staging/rtl8188eu/core/rtw_security.c:517: warning: Function parameter or member 'rc4key' not described in 'phase2'
 drivers/staging/rtl8188eu/core/rtw_security.c:517: warning: Function parameter or member 'tk' not described in 'phase2'
 drivers/staging/rtl8188eu/core/rtw_security.c:517: warning: Function parameter or member 'p1k' not described in 'phase2'
 drivers/staging/rtl8723bs/core/rtw_security.c:1937: warning: This comment starts with '/**', but isn't a kernel-doc comment. Refer Documentation/doc-guide/kernel-doc.rst

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-staging@lists.linux.dev
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lore.kernel.org/r/20210414181129.1628598-16-lee.jones@linaro.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rtl8723bs/core/rtw_security.c

@@ -1933,7 +1933,7 @@ const u8 rcons[] = {
 	/* for 128-bit blocks, Rijndael never uses more than 10 rcon values */
 };
 
-/**
+/*
  * Expand the cipher key into the encryption key schedule.
  *
  * @return	the number of rounds for the given cipher key size.