build: move the -j flag to package.mk instead of grabbing it from makeflags, otherwise it occasionally gets omitted on full builds

SVN-Revision: 33422

include/package.mk

@@ -16,7 +16,7 @@ PKG_BUILD_PARALLEL ?=
 PKG_INFO_DIR := $(STAGING_DIR)/pkginfo
 
 ifneq ($(CONFIG_PKG_BUILD_USE_JOBSERVER),)
-  MAKE_J:=$(MAKE_JOBSERVER)
+  MAKE_J:=$(if $(MAKE_JOBSERVER),$(MAKE_JOBSERVER) -j)
 else
   MAKE_J:=-j$(CONFIG_PKG_BUILD_JOBS)
 endif

include/toplevel.mk

@@ -148,7 +148,7 @@ prereq:: prepare-tmpinfo .config
 			echo "WARNING: your configuration is out of sync. Please run make menuconfig, oldconfig or defconfig!"; \
 		fi \
 	)
-	@+$(SUBMAKE) -r $@ MAKE_JOBSERVER="$(filter --jobserver% -j,$(MAKEFLAGS))"
+	@+$(SUBMAKE) -r $@ MAKE_JOBSERVER="$(filter --jobserver%,$(MAKEFLAGS))"
 
 help:
 	cat README