versioner: fix indentation in usage.

Test: versioner -h
Change-Id: I96cba65e53c564c8f47714c74d300e8f3dee7e82
diff --git a/tools/versioner/src/versioner.cpp b/tools/versioner/src/versioner.cpp
index e39bec0..194f276 100644
--- a/tools/versioner/src/versioner.cpp
+++ b/tools/versioner/src/versioner.cpp
@@ -435,7 +435,7 @@
     fprintf(stderr, "\n");
     fprintf(stderr, "Preprocessing:\n");
     fprintf(stderr, "  -o PATH\tpreprocess header files and emit them at PATH\n");
-    fprintf(stderr, "  -f\tpreprocess header files even if validation fails\n");
+    fprintf(stderr, "  -f\t\tpreprocess header files even if validation fails\n");
     fprintf(stderr, "\n");
     fprintf(stderr, "Miscellaneous:\n");
     fprintf(stderr, "  -d\t\tdump function availability\n");