builtin-rerere: fix a small leak

The data read from MERGE_RR file is kept in path-list by hanging textual
40-byte conflict signature to path of the blob that contains the
conflict.  The signature is strdup'ed twice, and the second copy is given
to the path-list, leaking the first copy.

Signed-off-by: Junio C Hamano <junio@pobox.com>
Acked-by: Johannes Schindelin <Johannes.Schindelin@gmx.de>
diff --git a/builtin-rerere.c b/builtin-rerere.c
index 5c81142..85222d9 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c
@@ -43,7 +43,7 @@
 			; /* do nothing */
 		if (i == sizeof(buf))
 			die("filename too long");
-		path_list_insert(buf, rr)->util = xstrdup(name);
+		path_list_insert(buf, rr)->util = name;
 	}
 	fclose(in);
 }