Fixing cell-build to apply patch only if necessary.
Fixing cell-build to apply patch only if necessary.

Change-Id: I08dcb74d2e421e4fe12c015b5afba1bf282896be

kuujo/onos,gkatsikas/onos,gkatsikas/onos,oplinkoms/onos,gkatsikas/onos,opennetworkinglab/onos,opennetworkinglab/onos,kuujo/onos,oplinkoms/onos,oplinkoms/onos,gkatsikas/onos,kuujo/onos,kuujo/onos,kuujo/onos,oplinkoms/onos,opennetworkinglab/onos,gkatsikas/onos,opennetworkinglab/onos,kuujo/onos,kuujo/onos,opennetworkinglab/onos,gkatsikas/onos,oplinkoms/onos,oplinkoms/onos,oplinkoms/onos,opennetworkinglab/onos