Robustify starting of ssh connection to vm updater.

bin/cros_run_vm_test

Index: bin/cros_run_vm_test
diff --git a/bin/cros_run_vm_test b/bin/cros_run_vm_test
index 8c7f68f97323cb313ff7db290fa87f03f13a52b0..2bcdcf088c9a50346d69f89d960dd739181b41aa 100755
--- a/bin/cros_run_vm_test
+++ b/bin/cros_run_vm_test
@@ -31,8 +31,6 @@ find_common_sh
 . "${SCRIPT_ROOT}/lib/cros_vm_constants.sh" || \
   die "Unable to load cros_vm_constants.sh"
 
-MAX_RETRIES=3
-
 get_default_board
 
 DEFINE_string board "$DEFAULT_BOARD" \
@@ -88,8 +86,7 @@ done
 
 trap stop_kvm EXIT
 start_kvm "${FLAGS_image_path}"
-info "Checking for ssh access to virtual machine."
-retry_until_ssh ${MAX_RETRIES}
+retry_until_ssh
 
 if [ -n "${FLAGS_verify_chrome_version}" ]; then
   info "Verifying version of Chrome matches what we expect."