Simplify call to nuget pack on ci (#533)

Author: Amaury Levé

src/Packaging/Packaging.csproj

@@ -165,7 +165,7 @@
   </Target>
 
   <Target Name="CreateNuGetPackage" Condition=" '$(TargetFramework)' == '$(ScannerNetCoreGlobalToolVersion)' AND $(Configuration) == 'Release' ">
-    <Exec WorkingDirectory="$(GlobalToolNuspecDir)" Command="&quot;$(NUGET_PATH)&quot; pack -OutputDirectory $(WorkDestinationRootDir) -Prop Configuration=Release" />
+    <Exec WorkingDirectory="$(GlobalToolNuspecDir)" Command="&quot;nuget&quot; pack -OutputDirectory $(WorkDestinationRootDir) -Prop Configuration=Release" />
   </Target>
 
 </Project>