f2fs_utils: fix build break in static_sdk_tools

external/f2fs-tools/mkfs/f2fs_format.c:357:
    error: undefined reference to dev_read_version
clang: error:
    linker command failed with exit code 1 (use -v to see invocation)
make: *** [out/host/linux-x86/obj/lib/libf2fs_fmt_host_dyn.so] Error 1

Change-Id: I9bf1eec9ee60aa2fc55a3d0793a67d36f271acef
diff --git a/f2fs_utils/f2fs_ioutils.c b/f2fs_utils/f2fs_ioutils.c
index 53b7b4b..f3b2a63 100644
--- a/f2fs_utils/f2fs_ioutils.c
+++ b/f2fs_utils/f2fs_ioutils.c
@@ -148,6 +148,11 @@
 /*
  * IO interfaces
  */
+int dev_read_version(void *buf, __u64 offset, size_t len)
+{
+        return 0;
+}
+
 int dev_read(void  *buf, __u64 offset, size_t len)
 {
 	return 0;