*.bbclass (shell): avoid pipe with sed

Replace:
cat <file> | sed -e xxx
By:
sed -e xxx <file>

(From OE-Core rev: e2026f5d32ac05396615224ac9ec927439e7e6b4)

Signed-off-by: Matthieu Crapet <Matthieu.Crapet@ingenico.com>
Signed-off-by: Saul Wold <sgw@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/classes/kernel-grub.bbclass

@@ -67,7 +67,7 @@ pkg_postinst_kernel-image_prepend () {
 		if [ "${grubcfg##*/}" = "grub.cfg" ]; then
 			cat "$grubcfg"
 		elif [ "${grubcfg##*/}" = "menu.list" ]; then
-			cat "$grubcfg" | sed -e '/^default/d' -e '/^timeout/d'
+			sed -e '/^default/d' -e '/^timeout/d' "$grubcfg"
 		fi
 	}