Release the fork lock when _kern_fork() failed or otherwise we'll

deadlock when trying the next fork().


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25600 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/system/libroot/posix/unistd/fork.c

@@ -147,6 +147,7 @@ fork(void)
 	thread = _kern_fork();
 	if (thread < 0) {
 		// something went wrong
+		release_sem(sForkLock);
 		errno = thread;
 		return -1;
 	}