fstools: update to the latest master branch

ff1ded6 libfstools: Fix overflow of F2FS_MINSIZE constant
bc2c876 libfstools: Print error in case of loop blkdev failure

Signed-off-by: Petr Štetiar <ynezz@true.cz>

package/system/fstools/Makefile

@@ -12,9 +12,9 @@ PKG_RELEASE:=4
 
 PKG_SOURCE_PROTO:=git
 PKG_SOURCE_URL=$(PROJECT_GIT)/project/fstools.git
-PKG_SOURCE_DATE:=2018-12-28
-PKG_SOURCE_VERSION:=af93f4b8dc32cf1320dfe8f4b93bb3a12606fc33
-PKG_MIRROR_HASH:=a2d8c2500fe75014ef16c039d8cdb276c1d5c066f8bce6550a3ecf46a9a411a9
+PKG_SOURCE_DATE:=2019-03-28
+PKG_SOURCE_VERSION:=ff1ded63c51e84e239fb422ac8b9d15251d1221f
+PKG_MIRROR_HASH:=2731bbca42c0eafda557d545ebeca243fa4048c433c3b27d31256aca356886bc
 CMAKE_INSTALL:=1
 
 PKG_LICENSE:=GPL-2.0