initfs: update: Consistently add ERROR: and print to stderr

Make sure all error messages start with the tag ERROR and its
printed to stderr by creating an echoerr function.

Previously one case had the file descriptors backwards in the
redirection.

Signed-off-by: Milton Miller <miltonm@us.ibm.com>
diff --git a/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh b/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
index f0ca989..e51dbf8 100755
--- a/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
+++ b/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
@@ -2,6 +2,10 @@
 
 echo update: "$@"
 
+echoerr() {
+	echo 1>&2 "ERROR: $@"
+}
+
 cd /
 if ! test -r /proc/mounts || ! test -f /proc/mounts
 then
@@ -21,7 +25,7 @@
 
 if grep mtd /proc/mounts
 then
-	echo 1>&2 "Error: A mtd device is mounted."
+	echoerr "A mtd device is mounted."
 	exit 1
 fi
 
@@ -90,7 +94,7 @@
 		toram=y
 		shift ;;
 	*)
-		echo 2>&1 "Unknown option $1"
+		echoerr "Unknown option $1"
 		exit 1 ;;
 	esac
 done
@@ -126,7 +130,7 @@
 	m=$(findmtd ${f#$image})
 	if test -z "$m"
 	then
-		echo 1>&2  "Unable to find mtd partiton for ${f##*/}."
+		echoerr "Unable to find mtd partiton for ${f##*/}."
 		exit 1
 	fi
 done