[source] build: make the touch .autoremove call non-fatal

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/807461e11c8e8d86f28fc642966eb1f83a3b08f1

commit 807461e11c8e8d86f28fc642966eb1f83a3b08f1
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Tue Jan 24 13:55:52 2017 +0100

    build: make the touch .autoremove call non-fatal
    
    Fixes build issues when there is nothing to do on the compile step (e.g.
    with unselected packages).
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/package.mk | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/package.mk b/include/package.mk
index 01c0333..91871f0 100644
--- a/include/package.mk
+++ b/include/package.mk
@@ -216,7 +216,7 @@ define Build/CoreTargets
 
   ifneq ($(CONFIG_AUTOREMOVE),)
     compile:
-		touch $(PKG_BUILD_DIR)/.autoremove
+		-touch $(PKG_BUILD_DIR)/.autoremove 2>/dev/null >/dev/null
 		$(FIND) $(PKG_BUILD_DIR) -mindepth 1 -maxdepth 1 -not '(' -type f -and -name '.*' -and -size 0 ')' -and -not -name '.pkgdir' | \
 			$(XARGS) rm -rf
   endif