Fix undetected cat_file failure

Index: ../../Mk/Scripts/do-patch.sh
===================================================================
--- ../../Mk/Scripts/do-patch.sh	(revision 553537)
+++ ../../Mk/Scripts/do-patch.sh	(working copy)
@@ -68,7 +68,7 @@
 		${dp_ECHO_MSG} "===>  Applying ${msg} ${file}${patch_strip:+ with ${patch_strip}}"
 	fi
 
-	if ! cat_file "$file" | do_patch "$@" ${patch_strip}; then
+	if ! cat_file "$file" > /dev/null || ! cat_file "$file" | do_patch "$@" ${patch_strip}; then
 		${dp_ECHO_MSG} "===>  FAILED Applying ${msg} ${file}${patch_strip:+ with ${patch_strip}}"
 		false
 	fi