mtd: mark as nonshared to fix FS#484

The mtd tool is built with different configurations depending on the
target. For example, brcm47xx adds the fixtrx subcommand, without which
an image fails when booting the second time.

Mark the mtd package as nonshared to really fix FS#484.

Signed-off-by: Mirko Parthey <mirko.parthey@web.de>

package/system/mtd/Makefile

@@ -17,6 +17,8 @@ STAMP_PREPARED := $(STAMP_PREPARED)_$(call confvar,CONFIG_MTD_REDBOOT_PARTS)
 PKG_LICENSE:=GPL-2.0+
 PKG_LICENSE_FILES:=
 
+PKG_FLAGS:=nonshared
+
 include $(INCLUDE_DIR)/package.mk
 
 define Package/mtd