Update the README.md of 1.child_inherit_flock

Correct one typo

process/1.child_inherit_flock/README.md

@@ -5,4 +5,4 @@ At that time, run this process again. You would find the second instance blocks
 
 # Conclusion
 
-The flock is shared between the parent and child process. Although the flock would be release automatically when process exist, it must be done until both of parent and child exit.
+The flock is shared between the parent and child process. Although the flock would be release automatically when process exits, it must be done until both of parent and child exit.