t: switch $_x40 to $OID_REGEX

Switch all uses of $_x40 to $OID_REGEX so that they work correctly with
larger hashes.  This commit was created by using the following sed
command to modify all files in the t directory except t/test-lib.sh:

  sed -i 's/\$_x40/$OID_REGEX/g'

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/t/t7506-status-submodule.sh b/t/t7506-status-submodule.sh
index 9edf657..b4b74db 100755
--- a/t/t7506-status-submodule.sh
+++ b/t/t7506-status-submodule.sh
@@ -18,7 +18,7 @@
 }
 
 sanitize_output () {
-	sed -e "s/$_x40/HASH/" -e "s/$_x40/HASH/" output >output2 &&
+	sed -e "s/$OID_REGEX/HASH/" -e "s/$OID_REGEX/HASH/" output >output2 &&
 	mv output2 output
 }