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)
 ...