liburcu: disable compilation optimizatoin

profiled applications for user-space tracing were crashing with segmentation
violation. disabling optimization for liburcu solves this problem

http://jira.alm.mentorg.com:8080/browse/SB-1143

Signed-off-by: Fahad Usman <fahad_usman@mentor.com>
(cherry picked from commit 7ff7f8aed0b8c4548a3a4df7217add9f847bb64c)

Signed-off-by: Michael Brown <mw_brown@mentor.com>