PFW: Fixed bug when entering empty rule

BZ: 24081

When entering an empty rule (composed of spaces), the PFW used to
crash.
Now an error message is displayed : "Syntax error, no rule found".

Change-Id: If3cb505f879d006309add46d5c7c4f47325af563
Reviewed-on: http://android.intel.com:8080/35613
Reviewed-by: Boisnard, FredericX <fredericx.boisnard@intel.com>
Reviewed-by: Denneulin, GuillaumeX <guillaumex.denneulin@intel.com>
Reviewed-by: Centelles, Sylvain <sylvain.centelles@intel.com>
Tested-by: Barthes, FabienX <fabienx.barthes@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>
1 file changed