investigate flaky sequential/test-regress-GH-897 on Raspberry Pi

[Trott]

https://ci.nodejs.org/job/node-test-binary-arm/4936/RUN_SUBSET=6,label=pi1-raspbian-wheezy/console

not ok 177 sequential/test-regress-GH-897
  ---
  duration_ms: 2.464
  severity: fail
  stack: |-
    
    assert.js:85
      throw new assert.AssertionError({
      ^
    AssertionError: timer fired after 104 ms
        at Timeout.<anonymous> (/home/iojs/build/workspace/node-test-binary-arm/test/sequential/test-regress-GH-897.js:16:10)
        at Timeout._onTimeout (/home/iojs/build/workspace/node-test-binary-arm/test/common.js:416:15)
        at ontimeout (timers.js:365:14)
        at tryOnTimeout (timers.js:237:5)
        at Timer.listOnTimeout (timers.js:207:5)

[Trott]

Failed again today:

https://ci.nodejs.org/job/node-test-binary-arm/5976/RUN_SUBSET=5,label=pi1-raspbian-wheezy/console

not ok 186 sequential/test-regress-GH-897
  ---
  duration_ms: 2.148
  severity: fail
  stack: |-
    
    assert.js:85
      throw new assert.AssertionError({
      ^
    AssertionError: timer fired after 100 ms
        at Timeout.<anonymous> (/home/iojs/build/workspace/node-test-binary-arm/test/sequential/test-regress-GH-897.js:16:10)
        at Timeout._onTimeout (/home/iojs/build/workspace/node-test-binary-arm/test/common.js:446:15)
        at ontimeout (timers.js:365:14)
        at tryOnTimeout (timers.js:237:5)
        at Timer.listOnTimeout (timers.js:207:5)
  ...