lunch: error on >1 arg (before ignored)

Bug: N/A
Test: lunch w/ 0, 1, and 2 args
Change-Id: Icbeb511e836b08cbd64b08a23b0e4820039b12ab

envsetup.sh

@@ -599,7 +599,12 @@ function lunch()
 {
     local answer
 
-    if [ "$1" ] ; then
+    if [[ $# -gt 1 ]]; then
+        echo "usage: lunch [target]" >&2
+        return 1
+    fi
+
+    if [ "$1" ]; then
         answer=$1
     else
         print_lunch_menu