Removed test code in Invoke-ShellcodeMSIL

There was some test code at the end of Invoke-ShellcodeMSIL that would
cause the function to execute when the script was dotsourced.

CodeExecution/Invoke-ShellcodeMSIL.ps1

@@ -264,7 +264,4 @@
     {
         Write-Verbose 'Shellcode executed successfully!'
     }
-}
-
-$Shellcode = [Byte[]]@(0x90,0x90,0x90,0x90,0x90,0x90,0xC3)
-Invoke-ShellcodeMSIL -Shellcode $Shellcode -Verbose
+}