test_brk_collision in ubuntu_qrt_kernel_aslr_collisions failed on T

Issue found on 3.13.0-190.241 lowlatency kernel with node gonzo (passed with generic kernel on another node onibi)

Manually tested with:
  * node "onibi" + 3.13.0-190 lowlatency kernel: passed
  * node "onibi" + 3.13.0-170 generic kernel: passed
  * node "gonzo" + 3.13.0-190 generic kernel: failed
  * node "gonzo" + 3.13.0-189 generic kernel: failed
  * node "gonzo" + 3.13.0-170 generic kernel: failed

Looks like this is not a regression but rather a hardware-specific issue.

Test fail rate 5 out of 5 attempts.

Test log:
 test_brk_collision (__main__.KernelASLRCollisionsTest)
 Check if brk crashes into mmap in 10,000 execs (i386, nx-emu only) (LP: #452175) ... FAIL
 test_stack_collision (__main__.KernelASLRCollisionsTest)

 Check if stack crashes into mmap in 100,000 execs (amd64 only?) (LP: #504164) ... ok

 ======================================================================
 FAIL: test_brk_collision (__main__.KernelASLRCollisionsTest)
 Check if brk crashes into mmap in 10,000 execs (i386, nx-emu only) (LP: #452175)
 ----------------------------------------------------------------------
 Traceback (most recent call last):
   File "./test-kernel-aslr-collisions.py", line 95, in test_brk_collision
     self.assertShellExitEquals(0, ['./explode-brk'])
   File "/home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_aslr_collisions/src/qa-regression-testing/scripts/testlib.py", line 1203, in assertShellExitEquals
     self.assertEqual(expected, rc, msg + result + report)
 AssertionError: Got exit code 1, expected 0
 Command: './explode-brk'
 Output:
 7f59c8fd8000-7f59c9196000 r-xp 00000000 08:01 3281122 /lib/x86_64-linux-gnu/libc-2.19.so
 7f59c9196000-7f59c9396000 ---p 001be000 08:01 3281122 /lib/x86_64-linux-gnu/libc-2.19.so
 7f59c9396000-7f59c939a000 r--p 001be000 08:01 3281122 /lib/x86_64-linux-gnu/libc-2.19.so
 7f59c939a000-7f59c939c000 rw-p 001c2000 08:01 3281122 /lib/x86_64-linux-gnu/libc-2.19.so
 7f59c939c000-7f59c93a1000 rw-p 00000000 00:00 0
 7f59c93a8000-7f59c93cb000 r-xp 00000000 08:01 3281111 /lib/x86_64-linux-gnu/ld-2.19.so
 7f59c95ca000-7f59c95cb000 r--p 00022000 08:01 3281111 /lib/x86_64-linux-gnu/ld-2.19.so
 7f59c95cb000-7f59c95cc000 rw-p 00023000 08:01 3281111 /lib/x86_64-linux-gnu/ld-2.19.so
 7f59c95cc000-7f59c95cd000 rw-p 00000000 00:00 0
 7f59c95d0000-7f59c95d1000 r-xp 00000000 08:01 15470803 /home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_aslr_collisions/src/qa-regression-testing/scripts/kernel-aslr-collisions/explode-brk
 7f59c97d0000-7f59c97d1000 r--p 00000000 08:01 15470803 /home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_aslr_collisions/src/qa-regression-testing/scripts/kernel-aslr-collisions/explode-brk
 7f59c97d1000-7f59c97d2000 rw-p 00001000 08:01 15470803 /home/ubuntu/autotest/client/tmp/ubuntu_qrt_kernel_aslr_collisions/src/qa-regression-testing/scripts/kernel-aslr-collisions/explode-brk
 7f59c97d4000-7f59c97d8000 rw-p 00000000 00:00 0 [heap]
 7fffd59ff000-7fffd5a20000 rw-p 00000000 00:00 0 [stack]
 7fffd5a20000-7fffd5a22000 r-xp 00000000 00:00 0 [vdso]
 ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall]
 FAIL: unable to use brk area at 0x7f59c97d4000 - 0x7f59c97dc000

 ----------------------------------------------------------------------
 Ran 5 tests in 467.450s

 FAILED (failures=1)

No output printed in /var/log/syslog