Minor cleanup in __kmp_atfork_child()

[hbae]

Summary

This change removes the unnecessary lock operation on __kmp_initz_lock inside the __kmp_atfork_child() function for Linux; the lock variable is initialized in the same function later.

[AndreyChurbanov]

LGTM

runtime/src/z_Linux_util.cpp

static void __kmp_atfork_parent(void) {
   __kmp_release_bootstrap_lock(&__kmp_initz_lock);
   __kmp_release_bootstrap_lock(&__kmp_forkjoin_lock);
 }
 
 /* Reset the library so execution in the child starts "all over again" with
    clean data structures in initial states.  Don't worry about freeing memory
    allocated by parent, just abandon it to be safe. */
 static void __kmp_atfork_child(void) {
-  __kmp_release_bootstrap_lock(&__kmp_initz_lock);
   __kmp_release_bootstrap_lock(&__kmp_forkjoin_lock);
   /* TODO make sure this is done right for nested/sibling */
   // ATT:  Memory leaks are here? TODO: Check it and fix.
   /* KMP_ASSERT( 0 ); */
 
   ++__kmp_fork_count;
 
 #if KMP_AFFINITY_SUPPORTED