[tools] Fix error message for patch failure

Minor fix: Provide a string for "%s".

R=hablich@chromium.org

Change-Id: Ibae24688c5f69e0fee5108701aa7f483117aea8c
Reviewed-on: https://chromium-review.googlesource.com/457998Reviewed-by: Michael Hablich <hablich@chromium.org>
Commit-Queue: Clemens Hammacher <clemensh@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44350}

tools/release/common_includes.py

@@ -611,7 +611,7 @@ class Step(GitRecipesMixin):
   def WaitForResolvingConflicts(self, patch_file):
     print("Applying the patch \"%s\" failed. Either type \"ABORT<Return>\", "
           "or resolve the conflicts, stage *all* touched files with "
-          "'git add', and type \"RESOLVED<Return>\"")
+          "'git add', and type \"RESOLVED<Return>\"" % (patch_file))
     self.DieNoManualMode()
     answer = ""
     while answer != "RESOLVED":