[source] build: fix bin/ package empty check

[LEDE Commits]

nbd pushed a commit to source.git, branch master:
https://git.lede-project.org/fb07085218859e0afe033d8a32ac2618303911ff

commit fb07085218859e0afe033d8a32ac2618303911ff
Author: Felix Fietkau <nbd at nbd.name>
AuthorDate: Mon Jan 23 12:32:04 2017 +0100

    build: fix bin/ package empty check
    
    $(wildcard) is evaluated too early in the build process
    
    Signed-off-by: Felix Fietkau <nbd at nbd.name>
---
 include/package-bin.mk | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/include/package-bin.mk b/include/package-bin.mk
index 3d0baad..68f5831 100644
--- a/include/package-bin.mk
+++ b/include/package-bin.mk
@@ -27,10 +27,12 @@ ifeq ($(DUMP),)
 		touch $$@
 
     install-bin-$(1): $(PKG_BUILD_DIR)/.pkgdir/$(1).installed
-	  rm -rf $(BIN_DIR)/$(1)
-	  $(if $(wildcard $(PKG_BUILD_DIR)/.pkgdir/$(1)/*), \
-		$(INSTALL_DIR) $(BIN_DIR)/$(1) && $(CP) $(PKG_BUILD_DIR)/.pkgdir/$(1)/. $(BIN_DIR)/$(1)/ \
-	  )
+	rm -rf $(BIN_DIR)/$(1)
+	-rmdir $(PKG_BUILD_DIR)/.pkgdir/$(1) >/dev/null 2>/dev/null
+	[ -d $(PKG_BUILD_DIR)/.pkgdir/$(1) ] && { \
+		$(INSTALL_DIR) $(BIN_DIR)/$(1) && \
+		$(CP) $(PKG_BUILD_DIR)/.pkgdir/$(1)/. $(BIN_DIR)/$(1)/; \
+	}
 
     clean-$(1):
 	  rm -rf $(BIN_DIR)/$(1)