vboot_reference: remove trailing newline/space for make_dev_ssd

To make the output of kernel_config from make_dev_ssd more close to the original
images, we should eliminate the trailing newline/space.

BUG=chromium-os:13516
TEST=make_dev_ssd.sh # succcess

Change-Id: I17f030f8815dea22b04058456d98db6911888ef6

R=rspangler@chromium.org,clchiou@chromium.org

Review URL: http://codereview.chromium.org/6735009
diff --git a/scripts/image_signing/make_dev_ssd.sh b/scripts/image_signing/make_dev_ssd.sh
index fb27bb2..df9bff7 100755
--- a/scripts/image_signing/make_dev_ssd.sh
+++ b/scripts/image_signing/make_dev_ssd.sh
@@ -159,7 +159,7 @@
     fi
 
     local new_kernel_config_file="$(make_temp_file)"
-    echo "$kernel_config"  >"$new_kernel_config_file"
+    echo -n "$kernel_config"  >"$new_kernel_config_file"
 
     debug_msg "Re-signing $name from $old_blob to $new_blob"
     debug_msg "Using key: $KERNEL_DATAKEY"