git-p4: Fix error message crash in P4Sync.commit.

There is an error message that crashes the script because of an invalid ref
to the non-existing "path" variable. It is almost never printed, which
would explain why nobody encountered this problem before... But anyway,
this oneliner fixes it.

Signed-off-by: Tor Arvid Lund <torarvid@gmail.com>
Acked-by: Pete Wyckoff <pw@padd.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

contrib/fast-import/git-p4

@@ -1160,7 +1160,7 @@ class P4Sync(Command):
             if [p for p in branchPrefixes if p4PathStartsWith(f['path'], p)]:
                 new_files.append (f)
             else:
-                sys.stderr.write("Ignoring file outside of prefix: %s\n" % path)
+                sys.stderr.write("Ignoring file outside of prefix: %s\n" % f['path'])
 
         self.gitStream.write("commit %s\n" % branch)
 #        gitStream.write("mark :%s\n" % details["change"])