gifn: grep + awk = awk

Change-Id: Ib0776ca7b74e7d50a5facf51e270d50e6658e2a8
diff --git a/tools/git-if-needed/sh/git-if-needed b/tools/git-if-needed/sh/git-if-needed
index 82f4331..a8e5666 100755
--- a/tools/git-if-needed/sh/git-if-needed
+++ b/tools/git-if-needed/sh/git-if-needed
@@ -28,7 +28,7 @@
 	fi
 
 	local chgid=''
-	chgid="$(grep -Ee '^[[:space:]]*Change-Id:[[:space:]]+I[0-9a-f]+$' -- "$fname" | awk '{ print $2 }')"
+	chgid="$(awk -- '/^[[:space:]]*Change-Id:[[:space:]]+I[0-9a-f]+$/ { print $2 }' "$fname")"
 	if ! expr "x$chgid" : 'xI[0-9a-f][0-9a-f]*$' > /dev/null; then
 		echo "Expected a single Change-Id line in $fname" 1>&2
 		exit 1