examples/performance-thread: fix build with clang 12.0.1

[ upstream commit 5e184c4 ]

In clang 12.0.1 version, the use of pthread_yield() is deprecated,
use sched_yield() instead.

log:
    examples/performance-thread/pthread_shim/main.c:75:9: warning:
    'pthread_yield' is deprecated: pthread_yield is deprecated,
    use sched_yield instead [-Wdeprecated-declarations]

Bugzilla ID: 745
Fixes: 433ba62 ("examples/performance-thread: add pthread_shim app")

Signed-off-by: Jerin Jacob <jerinj@marvell.com>
Tested-by: Ali Alnubani <alialnu@nvidia.com>

examples/performance-thread/pthread_shim/main.c

@@ -71,7 +71,7 @@ void *helloworld_pthread(void *arg)
 	print_count++;
 
 	/* yield thread to give opportunity for lock contention */
-	pthread_yield();
+	sched_yield();
 
 	/* retrieve arg from TLS */
 	uint64_t thread_no = (uint64_t) pthread_getspecific(key);