obmc-initfs: look for images in /run/initramfs/image-

Teach update to look for /run/initramfs/image- not /image-*.

When describing how to recover from a corrupted flash by grabbing
the images and running update from the init debug shell, it
became apparent that while at systemd shutdown /run/initramfs/
is mounted at /, it is not the case during init.  Use the
variable image to hold this pathname.

Signed-off-by: Milton Miller <miltonm@us.ibm.com>
diff --git a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
index 1122e83..f83b1ad 100755
--- a/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
+++ b/meta-phosphor/common/recipes-phosphor/obmc-phosphor-initfs/files/obmc-update.sh
@@ -61,10 +61,10 @@
 	umount rw
 fi
 
-
-for f in image-*
+image=/run/initramfs/image-
+for f in $image*
 do
-	m=$(findmtd ${f#image-})
+	m=$(findmtd ${f#$image})
 	if test -z "$m"
 	then
 		echo 1>&2  "Unable to find mtd partiton for $f"
@@ -72,10 +72,10 @@
 	fi
 done
 
-for f in image-*
+for f in $image*
 do
-	m=$(findmtd ${f#image-})
-	echo "Updating ${f#image-}"
+	m=$(findmtd ${f#$image})
+	echo "Updating ${f#$image}..."
 	# flasheraseall /dev/$m && dd if=$f of=/dev/$m
 	flashcp -v $f /dev/$m
 done