doc: fixed some links

Change-Id: I8563a20a4ba43cee7d4b73377c405a6ff12636e5
GitHub-Last-Rev: 0dae408845c7cf42667a65fff6f7d1a382e2d320
GitHub-Pull-Request: golang/go#31914
Reviewed-on: https://go-review.googlesource.com/c/go/+/176017Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>

src/crypto/elliptic/p256_asm_s390x.s

@@ -2465,7 +2465,7 @@ TEXT ·p256PointDoubleAsm(SB), NOSPLIT, $0
 #define PL    V30
 #define PH    V31
 /*
- * https://choucroutage.com/Papers/SideChannelAttacks/ctrsa-2011-brown.pdf "Software Implementation of the NIST Elliptic Curves Over Prime Fields"
+ * https://delta.cs.cinvestav.mx/~francisco/arith/julio.pdf "Software Implementation of the NIST Elliptic Curves Over Prime Fields"
  *
  * A = X₁×Z₂²
  * B = Y₁×Z₂³

src/runtime/write_err_android.go

@@ -21,7 +21,7 @@ var (
 // in kernel ring buffers. In Android-L, those /dev/log files are no longer
 // accessible and logging is done through a centralized user-mode logger, logd.
 //
-// https://android.googlesource.com/platform/system/core/+/master/liblog/logd_write.c
+// https://android.googlesource.com/platform/system/core/+/refs/tags/android-6.0.1_r78/liblog/logd_write.c
 type loggerType int32
 
 const (