Update check_series,sh to validate first line of patches

scripts/check_series.sh

@@ -30,6 +30,11 @@ do
       ERRORS=`expr $ERRORS + 1`
       echo $i appears $COUNT times in series
     fi
+    if head -1 $i | grep -v '# HG changeset patch' >/dev/null
+    then
+      ERRORS=`expr $ERRORS + 1`
+      echo bad hg header in $i
+    fi
   fi
 done
 for i in `cat series`