Fix libc compilation

svn:r4497

src/common/compat.c

@@ -147,7 +147,7 @@ tor_memmem(const void *_haystack, size_t hlen, const void *_needle, size_t nlen)
 {
 #if defined(HAVE_MEMMEM) && (!defined(__GNUC__) || __GNUC__ >= 2)
   tor_assert(nlen);
-  return memmem(haystack, hlen, needle, nlen);
+  return memmem(_haystack, hlen, _needle, nlen);
 #else
   /* This isn't as fast as the GLIBC implementation, but it doesn't need to be. */
   const char *p, *end;