upstream: Treat doas with arguments as a valid SUDO variable.

Allows one to specify SUDO="doas -n" which I do while running make regress.

ok dtucker@

OpenBSD-Regress-ID: 4fe5814b5010dbf0885500d703bea06048d11005

regress/agent-getpeereid.sh

@@ -15,7 +15,7 @@ else
 fi
 case "x$SUDO" in
 	xsudo) sudo=1;;
-	xdoas) ;;
+	xdoas|xdoas\ *) ;;
 	x)
 		echo "need SUDO to switch to uid $UNPRIV"
 		echo SKIPPED