soc: qcom: guestvm_loader: fix vm start print message

Fix vm start message. Currently the return value of vm start is
checked wronly and printing a wrong message though VM starts
successfully.

Change-Id: I57677bdd723695951e8c05b52fc9363863a02e2e
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>