build: remove redundant call to $(SH_FUNC) (#8042)

SVN-Revision: 30818

include/package-defaults.mk

@@ -50,7 +50,7 @@ endef
 Build/Patch:=$(Build/Patch/Default)
 ifneq ($(strip $(PKG_UNPACK)),)
   define Build/Prepare/Default
-	$(SH_FUNC) $(PKG_UNPACK)
+	$(PKG_UNPACK)
 	$(Build/Patch)
   endef
 endif