BaseTools: Fix PcdValueInit tool build issue with VS compiler x64

REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3001

When the 64-bit version of VS compiler is used, the generated
PcdValueInit tool will be failed to compile.

This patch is going to fix that issue.

Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <gaoliming@byosoft.com.cn>
Cc: Yuwei Chen <yuwei.chen@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Sean Brogan <sean.brogan@microsoft.com>
Reviewed-by: Sean Brogan <sean.brogan@microsoft.com>
Reviewed-by: Liming Gao <gaoliming@byosoft.com.cn>