hub_discovery/nfdc: wait for fresh nfd-status output

NFD may cache StatusDataset for up to one second,
but we need fresh dataset to see changes.

refs #2501, #2502

Change-Id: I34b68ffc8d148c864c034f5fba340c8f8bc37228
diff --git a/test_nfdc/include.sh b/test_nfdc/include.sh
index 5f1c491..9ad43b5 100755
--- a/test_nfdc/include.sh
+++ b/test_nfdc/include.sh
@@ -35,6 +35,9 @@
   counterType=$3
   threshold=$4
 
+  # wait for the refreshed output of nfd-status
+  sleep 2
+
   outCounter=$(nfd-status | grep -iF 'faceid='$faceId' remote='$faceUri | grep -Po $counterType={[0-9]+ | sed 's/'$counterType'={//')
 
 
@@ -58,6 +61,9 @@
   faceId=$1
   faceUri=$2
 
+  # wait for the refreshed output of nfd-status
+  sleep 2
+
   # check for the existence of the face
   # First, get the face line
   # Second, extract the face id attached to the fetched line
@@ -97,6 +103,9 @@
     exit 2
   fi
 
+  # wait for the refreshed output of nfd-status
+  sleep 2
+
   # check the existence of prefix FIB entry
   fibEntry=$(nfd-status | grep $prefix)
   if [[ -z "$fibEntry" ]]; then
@@ -117,4 +126,4 @@
     clean_up
     exit 2
   fi
-}
\ No newline at end of file
+}