(PUP-2509) Add -H flag to svcs to strip column headers

Without this flag, self.instances returns an entry for a service named
'FMRI':

$ puppet resource service

service { 'FMRI':
  ensure => 'stopped',
    enable => 'false',
}

<...>

This is from the header:

$ svcs | head -5
STATE          STIME    FMRI     <-----
legacy_run     Jun_22   lrc:/etc/rc2_d/S47pppd
legacy_run     Jun_22   lrc:/etc/rc2_d/S89PRESERVE
disabled       Jun_22   svc:/platform/i86pc/acpihpd:default
online         Jun_22   svc:/system/early-manifest-import:default

lib/puppet/provider/service/smf.rb

@@ -32,7 +32,7 @@ def setupservice
   end
 
   def self.instances
-   svcs.split("\n").select{|l| l !~ /^legacy_run/ }.collect do |line|
+   svcs("-H").split("\n").select{|l| l !~ /^legacy_run/ }.collect do |line|
      state,stime,fmri = line.split(/\s+/)
      status =  case state
                when /online/; :running

spec/unit/provider/service/smf_spec.rb

@@ -28,7 +28,7 @@
     end
 
     it "should get a list of services (excluding legacy)" do
-      provider_class.expects(:svcs).with().returns File.read(my_fixture('svcs.out'))
+      provider_class.expects(:svcs).with('-H').returns File.read(my_fixture('svcs.out'))
       instances = provider_class.instances.map { |p| {:name => p.get(:name), :ensure => p.get(:ensure)} }
       # we dont manage legacy
       expect(instances.size).to eq(2)