build: fix bin/ package empty check

$(wildcard) is evaluated too early in the build process

Signed-off-by: Felix Fietkau <nbd@nbd.name>

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)