otautil: #include <errno.h> for TEMP_FAILURE_RETRY.

Test: mmma bootable/recovery
Change-Id: I5959303528c6f704f10ce153f6fcb2054ce35b1e
diff --git a/otautil/SysUtil.cpp b/otautil/SysUtil.cpp
index 0655c47..48336ad 100644
--- a/otautil/SysUtil.cpp
+++ b/otautil/SysUtil.cpp
@@ -16,6 +16,7 @@
 
 #include "otautil/SysUtil.h"
 
+#include <errno.h>  // TEMP_FAILURE_RETRY
 #include <fcntl.h>
 #include <stdint.h>  // SIZE_MAX
 #include <sys/mman.h>