BaseTools/UPT: Fix UNI file name issue

Fix the issue of creating duplicate UNI file names
Fix the issue of removing packages

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hess Chen <hesheng.chen@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>

BaseTools/Source/Python/UPT/Core/DependencyRules.py

@@ -55,6 +55,8 @@ class DependencyRules(object):
         self.PkgsToBeDepend.extend(self.GenToBeInstalledPkgList(ToBeInstalledPkgList))
         
     def GenToBeInstalledPkgList(self, ToBeInstalledPkgList):
+        if not ToBeInstalledPkgList:
+            return []
         RtnList = []
         for Dist in ToBeInstalledPkgList:
             for Package in Dist.PackageSurfaceArea: