[Issue 1136] Introduce comments to indicate critical section in JBM
* Comment added to critical section in alloc/free data in jbm_jb4sb.c
Signed-off-by: 
Singh, Ripinder <ripinder.singh@dolby.com>
* Comment added to critical section in alloc/free data in jbm_jb4sb.c
Signed-off-by: Singh, Ripinder <ripinder.singh@dolby.com>