Control fault injection with config files instead of build flags

Bug: 26570379
Change-Id: I76109d09276d6e3ed3a32b6fedafb2582f545c0c
(cherry picked from commit d940887dde23597dc358b16d96ca48dd7480fee6)
diff --git a/otafault/test.cpp b/otafault/test.cpp
index a0f7315..6514782 100644
--- a/otafault/test.cpp
+++ b/otafault/test.cpp
@@ -17,16 +17,18 @@
 #include <errno.h>
 #include <fcntl.h>
 #include <stdio.h>
+#include <unistd.h>
 
 #include "ota_io.h"
 
-int main(int argc, char **argv) {
+int main(int /* argc */, char** /* argv */) {
     int fd = open("testdata/test.file", O_RDWR);
     char buf[8];
-    char *out = "321";
+    const char* out = "321";
     int readv = ota_read(fd, buf, 4);
     printf("Read returned %d\n", readv);
     int writev = ota_write(fd, out, 4);
     printf("Write returned %d\n", writev);
+    close(fd);
     return 0;
 }