Code quality improvement

Author: tamasvajk

csharp/autobuilder/Semmle.Autobuild.Shared/BuildActions.cs

@@ -252,7 +252,7 @@ bool IBuildActions.IsRunningOnAppleSilicon()
 
             try
             {
-                var res = thisBuildActions.RunProcess("sysctl", "machdep.cpu.brand_string", workingDirectory: null, env: null, out var stdOut);
+                thisBuildActions.RunProcess("sysctl", "machdep.cpu.brand_string", workingDirectory: null, env: null, out var stdOut);
                 return stdOut?.Any(s => s?.ToLowerInvariant().Contains("apple") == true) ?? false;
             }
             catch (Exception)

csharp/autobuilder/Semmle.Autobuild.Shared/MsBuildRule.cs

@@ -15,14 +15,12 @@ internal static class MsBuildCommandExtensions
         /// <returns></returns>
         public static CommandBuilder MsBuildCommand(this CommandBuilder cmdBuilder, IAutobuilder<AutobuildOptionsShared> builder)
         {
-            var IsRunningOnAppleSiliconMac = builder.Actions.IsMacOs() && builder.Actions.IsRunningOnAppleSilicon();
-
             // mono doesn't ship with `msbuild` on Arm-based Macs, but we can fall back to
             // msbuild that ships with `dotnet` which can be invoked with `dotnet msbuild`
             // perhaps we should do this on all platforms?
-            return IsRunningOnAppleSiliconMac ?
-                cmdBuilder.RunCommand("dotnet").Argument("msbuild") :
-                cmdBuilder.RunCommand("msbuild");
+            return builder.Actions.IsRunningOnAppleSilicon()
+                ? cmdBuilder.RunCommand("dotnet").Argument("msbuild")
+                : cmdBuilder.RunCommand("msbuild");
         }
     }