libsparse: allow including from C++

Change-Id: I3788fd07e2b52430a410f85fb79dc886c6a07fea
diff --git a/libsparse/include/sparse/sparse.h b/libsparse/include/sparse/sparse.h
index 17d085c..8b757d2 100644
--- a/libsparse/include/sparse/sparse.h
+++ b/libsparse/include/sparse/sparse.h
@@ -20,6 +20,10 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
 struct sparse_file;
 
 /**
@@ -273,4 +277,8 @@
  */
 extern void (*sparse_print_verbose)(const char *fmt, ...);
 
+#ifdef	__cplusplus
+}
+#endif
+
 #endif