ci: fix start_powershell_command so that $? is accessible

Author: aramprice

ci/tasks/install-windows-updates/run.sh

@@ -19,19 +19,11 @@ function start_powershell_command() {
   local powershell_command="${1}"
 
   echo "Starting '${powershell_command}'" >&2
-  pid=$(
-    govc guest.start \
-      -vm.ipath="${vm_ipath}" \
-      -l="${vm_username}:${vm_password}" \
-      "\\Windows\\System32\\WindowsPowerShell\\V1.0\\powershell.exe" \
-      "${powershell_command}"
-    )
-
-  if [ -z "${pid}" ]; then
-    echo "No PID returned when invoking '${powershell_command}'" >&2
-  fi
-
-  echo "${pid}"
+  govc guest.start \
+    -vm.ipath="${vm_ipath}" \
+    -l="${vm_username}:${vm_password}" \
+    "\\Windows\\System32\\WindowsPowerShell\\V1.0\\powershell.exe" \
+    "${powershell_command}"
 }
 
 function get_powershell_pid_exit_code() {