LU-15484 tests: Increase timeout to wait for child

LU-15484 tests: Increase timeout to wait for child

Sanity-pcc 101a is failing because the remote 'sleep 600'
process is not always started in time, meaning the NS
doesn't exist.

Increase the wait time for this process to start.

Lustre-change: https://review.whamcloud.com/46764
Lustre-commit: 94925be0ff6af31aa396d39265a5252de5557897

Fixes: f3be560031 "LU-15170 llite: Switch pcc to lookup_one_len"

Test-Parameters: trivial
Test-Parameters: testlist=sanity-pcc env="ONLY=101a,ONLY_REPEAT=50"
Signed-off-by: Patrick Farrell <pfarrell@whamcloud.com>
Change-Id: I57175ec2f0e948045cf88d4a13a1e56cc34f8407
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/47733
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Yang Sheng <ys@whamcloud.com>
Reviewed-by: Oleg Drokin <green@whamcloud.com>