Fix exit status for many vm commands

The pattern "[ $? -ne 0 ] && util::err ..." is problematic since it
leaves an exit status of 1 if the test fails, which is the non-error
case. So various commands (e.g., vm datastore add) return status 1 even
when they succeed if this pattern appears as the last line of a command
implementation.

Fix this by mechanically converting this pattern to
"[ $? -eq 0 ] || util:err ...".

lib/vm-util

@@ -44,7 +44,7 @@ util::load_module(){
     kldstat -qm ${_mod} >/dev/null 2>&1
     if [ $? -ne 0 ]; then
         kldload ${_mod} >/dev/null 2>&1
-        [ $? -ne 0 ] && util::err "unable to load ${_mod}.ko!"
+        [ $? -eq 0 ] || util::err "unable to load ${_mod}.ko!"
     fi
 }