Add get_{pv|vg|lv}_field() nightly test helper functions.

Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>

test/lvm-utils.sh

@@ -87,6 +87,28 @@ fi
   test $val1 = $val2
 }
 
+
+get_pv_field() {
+	local pv=$1
+	local field=$2
+	local value
+	pvs --noheading -o $field $pv | sed 's/^ *//'
+}
+
+get_vg_field() {
+	local vg=$1
+	local field=$2
+	local value
+	vgs --noheading -o $field $vg | sed 's/^ *//'
+}
+
+get_lv_field() {
+	local lv=$1
+	local field=$2
+	local value
+	lvs --noheading -o $field $lv | sed 's/^ *//'
+}
+
 check_vg_field_()
 {
     local vg=$1;

test/t-vgchange-usage.sh

@@ -17,13 +17,6 @@ aux prepare_pvs 3
 pvcreate --metadatacopies 0 $dev1
 vgcreate $vg $devs
 
-get_vg_field() {
-	local vg=$1
-	local field=$2
-	local value
-	vgs --noheading -o $field $vg | sed 's/^ *//'
-}
-
 vgdisplay $vg
 
 # vgchange -p MaxPhysicalVolumes (bz202232)