Run e2fsck on built sparse images.

Bug: 7591683
Change-Id: Id1cba79f7840aab1f0327cb741eda655b45d1b46
diff --git a/core/config.mk b/core/config.mk
index 61f72d2..16bcd69 100644
--- a/core/config.mk
+++ b/core/config.mk
@@ -298,6 +298,8 @@
 MAKE_EXT4FS := $(HOST_OUT_EXECUTABLES)/make_ext4fs$(HOST_EXECUTABLE_SUFFIX)
 MKEXTUSERIMG := $(HOST_OUT_EXECUTABLES)/mkuserimg.sh
 MKEXT2BOOTIMG := external/genext2fs/mkbootimg_ext2.sh
+SIMG2IMG := $(HOST_OUT_EXECUTABLES)/simg2img$(HOST_EXECUTABLE_SUFFIX)
+E2FSCK := $(HOST_OUT_EXECUTABLES)/e2fsck$(HOST_EXECUTABLE_SUFFIX)
 MKTARBALL := build/tools/mktarball.sh
 TUNE2FS := $(HOST_OUT_EXECUTABLES)/tune2fs$(HOST_EXECUTABLE_SUFFIX)
 E2FSCK := $(HOST_OUT_EXECUTABLES)/e2fsck$(HOST_EXECUTABLE_SUFFIX)