MinPlatformPkg/TestPointCheckLib: Remove unnecessary GetVariable2() call

The data buffer returned from the GetVariable2() call in
TestPointCheckMemoryTypeInformation() is not actually used or freed.

This change removes the unnecessary function call.

Cc: Chasel Chiu <chasel.chiu@intel.com>
Cc: Nate DeSimone <nathaniel.l.desimone@intel.com>
Cc: Isaac Oram <isaac.w.oram@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Eric Dong <eric.dong@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Isaac Oram <isaac.w.oram@intel.com>