LU-8062 ptlrpc: increase sleep time in ptlrpc_request_bufs_pack()

LU-8062 ptlrpc: increase sleep time in ptlrpc_request_bufs_pack()

schedule_timeout() does not necessarily expire. Increase the sleeping
time in ptlrpc_request_bufs_pack() as 2 seconds is too short, given
the 1 second sleep used for recovery-small test_115_write().

Test-Parameters: envdefinitions=ONLY=115 testlist=recovery-small,recovery-small,recovery-small,recovery-small
Test-Parameters: envdefinitions=ONLY=115 testlist=recovery-small,recovery-small,recovery-small,recovery-small
Test-Parameters: envdefinitions=ONLY=115 testlist=recovery-small,recovery-small,recovery-small,recovery-small
Test-Parameters: envdefinitions=ONLY=115 testlist=recovery-small,recovery-small,recovery-small,recovery-small

Lustre-commit: e9e744ea7352ea0d1a5d9b2bd05e0e7c19f08596
Lustre-change: https://review.whamcloud.com/26815

Change-Id: Ia1b1f096b500f67d26e5fa7c7fbd42642992f327
Signed-off-by: Vitaly Fertman <vitaly.fertman@seagate.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: James Simmons <uja.ornl@yahoo.com>
Reviewed-by: Fan Yong <fan.yong@intel.com>
Reviewed-on: https://review.whamcloud.com/28181
Tested-by: Jenkins
Tested-by: Maloo <hpdd-maloo@intel.com>
Reviewed-by: John L. Hammond <john.hammond@intel.com>