SecurityPkg/Pkcs7VerifyDxe: Cleanup P7CheckTrust function comments.

SecurityPkg/Pkcs7VerifyDxe: Cleanup P7CheckTrust function comments.

Delete description of non-existent parameters 'Content' and 'ContentSize' from P7CheckTrust() description.

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Qiu Shumin <shumin.qiu@intel.com>
Reviewed-by: Qin Long <qin.long@intel.com>
Reviewed-by: Leif Lindholm <leif.lindholm@linaro.org>
Reviewed-by: Jordan Justen <jordan.l.justen@intel.com>
git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@17937 6f19259b-4bc3-4df7-8a09-765794883524