otautil: Clean up SysUtil.cpp.

Add unit testcases for sysMapFile().

Test: recovery_unit_test passes.
Test: Build and use the new recovery image to sideload a package.
Test: Build and use the new recovery image to install an update.

Change-Id: I77d8f1ea151ab513865d992c256ba93a1fcb51a4
(cherry picked from commit c3292f3fcbb3cd608cc19b7459751fa5bb64ab84)
diff --git a/tests/Android.mk b/tests/Android.mk
index 8f19992..86591f7 100644
--- a/tests/Android.mk
+++ b/tests/Android.mk
@@ -18,7 +18,6 @@
 
 # Unit tests
 include $(CLEAR_VARS)
-LOCAL_CLANG := true
 LOCAL_CFLAGS := -Werror
 LOCAL_MODULE := recovery_unit_test
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
@@ -32,17 +31,19 @@
     libselinux \
     libbase
 
-LOCAL_SRC_FILES := unit/asn1_decoder_test.cpp
-LOCAL_SRC_FILES += unit/recovery_test.cpp
-LOCAL_SRC_FILES += unit/locale_test.cpp
-LOCAL_SRC_FILES += unit/zip_test.cpp
+LOCAL_SRC_FILES := \
+    unit/asn1_decoder_test.cpp \
+    unit/locale_test.cpp \
+    unit/recovery_test.cpp \
+    unit/sysutil_test.cpp \
+    unit/zip_test.cpp
+
 LOCAL_C_INCLUDES := bootable/recovery
 LOCAL_SHARED_LIBRARIES := liblog
 include $(BUILD_NATIVE_TEST)
 
 # Component tests
 include $(CLEAR_VARS)
-LOCAL_CLANG := true
 LOCAL_CFLAGS := -Werror
 LOCAL_ADDITIONAL_DEPENDENCIES := $(LOCAL_PATH)/Android.mk
 LOCAL_MODULE := recovery_component_test