tools/hotplug: 21549:8bcaec29574e breaks vif-script with arguments.

For example, (vif-script 'vif-bridge bridge=eth1') in xend-config.sxp will
cause vif-setup to attempt to execute 'vif-bridge bridge=eth1' due to a
quoting mismatch. The fix appears to be to remove the extra quotes around
"$script" in vif-setup.

Signed-off-by: Brendan Cully <brendan@cs.ubc.ca>
Signed-off-by: Ian Jackson <ian.jackson@eu.citrix.com>

tools/hotplug/Linux/vif-setup

@@ -2,7 +2,7 @@
 
 if test "$script"
 then
-    exec "$script" $*
+    exec $script $*
 else
     exec /etc/xen/scripts/vif-bridge $*
 fi