pthread_mutexattr_setrobust.3: EXAMPLE: show example run of program

Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>

man3/pthread_mutexattr_setrobust.3

@@ -184,6 +184,20 @@ The main thread subsequently acquires the mutex
 successfully and gets the error
 .BR EOWNERDEAD ,
 after which it makes the mutex consistent.
+.PP
+The following shell session shows what we see when running this program:
+.PP
+.in +4n
+.EX
+$ \fB./a.out\fP
+[original owner] Setting lock...
+[original owner] Locked. Now exiting without unlocking.
+[main thread] Attempting to lock the robust mutex.
+[main thread] pthread_mutex_lock() returned EOWNERDEAD
+[main thread] Now make the mutex consistent
+[main thread] Mutex is now consistent; unlocking
+.EE
+.in
 .SS Program source
 .EX
 #include <stdlib.h>