[jhbuild] Makefile.plain: fix the include-check rule so that it doesn't always fail

[Craig Keogh <cskeogh src gnome org>]

commit 78ba9dc1ee7854d2a71b29644e907ba3b7c9be98
Author: Thomas Wood <thos gnome org>
Date:   Fri Oct 28 12:55:09 2011 +0100

    Makefile.plain: fix the include-check rule so that it doesn't always fail

 Makefile.plain |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/Makefile.plain b/Makefile.plain
index 1222d54..70099cc 100644
--- a/Makefile.plain
+++ b/Makefile.plain
@@ -9,8 +9,8 @@ MAKE ?= make
 -include Makefile.inc
 
 include-check:
-	@test -f Makefile.inc || \
-	echo "Makefile.inc doesn't exist. Please run autogen.sh"; exit 1
+	test -f Makefile.inc || \
+	(echo "Makefile.inc doesn't exist. Please run autogen.sh"; exit 1)
 
 all: install-check
 	@echo 'Run "make install" to install.'