[sheepdog] [PATCH] makefile: fix an error when no args for 'rm'

[Liu Yuan]

From: Liu Yuan <tailai.ly at taobao.com>

UPDATE:
 - use 'rm -f' as Kazutaka suggests
-------------------- 8< ------------------

This patch fixes the following err for 'make clean':

...
find -name '*.orig' -or -name '*.rej' | xargs rm
rm: missing operand
Try `rm --help' for more information.
make[1]: *** [clean-generic] Error 123

Signed-off-by: Liu Yuan <tailai.ly at taobao.com>
---
 Makefile.am |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Makefile.am b/Makefile.am
index 2c9bcc8..c896316 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -30,7 +30,7 @@ dist-clean-local:
 
 clean-generic:
 	rm -rf $(SPEC) $(TARFILE) cscope*
-	find -name '*.orig' -or -name '*.rej' | xargs rm
+	find -name '*.orig' -or -name '*.rej' | xargs rm -f
 
 cscope:
 	@echo create cscope.out
-- 
1.7.10.2