fstools: Update to 2016-12-04

Brings in the following changes:
84b530a732b1 libfstools: Check return values for fread and system

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>

package/system/fstools/Makefile

@@ -12,9 +12,9 @@ PKG_RELEASE:=1
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(LEDE_GIT)/project/fstools.git
-PKG_SOURCE_DATE:=2016-09-31
-PKG_SOURCE_VERSION:=94a5b0ad8d53f024f036c3526b48c34ebbd66a2f
-PKG_MIRROR_HASH:=e6c7f8a2a9bce6f399cd206c786c130087843581e148098366f941154eb0c482
+PKG_SOURCE_DATE:=2016-12-04
+PKG_SOURCE_VERSION:=84b530a732b12cca1cd5ee9ba163b7ead7a83de3
+PKG_MIRROR_HASH:=b607138de1adbb7f49e53daebe28ac1352910fa2b29278365edeabafc5b46a91
 CMAKE_INSTALL:=1
 
 PKG_LICENSE:=GPL-2.0