init(8): signal handler boolean needs to be "volatile"

[Scott Cheloha]

The variable "clang" is modified from a signal handler.  It should be
of type sig_atomic_t and it needs to be volatile.

ok?

Index: init.c
===================================================================
RCS file: /cvs/src/sbin/init/init.c,v
retrieving revision 1.71
diff -u -p -r1.71 init.c
--- init.c      24 Oct 2021 21:24:21 -0000      1.71
+++ init.c      9 Sep 2022 19:03:08 -0000
@@ -176,7 +176,8 @@ void setsecuritylevel(int);
 void setprocresources(char *);
 int getsecuritylevel(void);
 int setupargv(session_t *, struct ttyent *);
-int clang;
+
+volatile sig_atomic_t clang;
 
 void clear_session_logs(session_t *);