NetworkPkg/TlsDxe: verify DataSize for EfiTlsCipherList

NetworkPkg/TlsDxe: verify DataSize for EfiTlsCipherList

TlsSetSessionData() shouldn't just ignore an incomplete EFI_TLS_CIPHER
element at the end of "Data":

- Generally speaking, malformed input for a security API is best rejected
  explicitly.

- Specifically speaking, the size of EFI_TLS_CIPHER is 2 bytes. If
  DataSize is 1 on input, then the initial check for (DataSize == 0) will
  fail, but then TlsSetCipherList() will be called with CipherNum=0.

Return EFI_INVALID_PARAMETER from TlsSetSessionData() if "Data" doesn't
contain a whole number of EFI_TLS_CIPHER elements. While at it, introduce
the dedicated variable CipherCount.

Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Cc: Siyuan Fu <siyuan.fu@intel.com>
Ref: https://bugzilla.tianocore.org/show_bug.cgi?id=915
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Laszlo Ersek <lersek@redhat.com>
Reviewed-by: Fu Siyuan <siyuan.fu@intel.com>
Reviewed-by: Long Qin <qin.long@intel.com>
Reviewed-by: Jiaxin Wu <jiaxin.wu@intel.com>