libsparse: add error reporting functions

Change-Id: I2f21355b6c5339d1d724b4c121ea30d575b2d366
diff --git a/libsparse/Android.mk b/libsparse/Android.mk
index dbe4d18..d3eeae6 100644
--- a/libsparse/Android.mk
+++ b/libsparse/Android.mk
@@ -6,7 +6,8 @@
         backed_block.c \
         output_file.c \
         sparse.c \
-        sparse_crc32.c
+        sparse_crc32.c \
+        sparse_err.c
 
 include $(CLEAR_VARS)