Fixed the return type and args struct tag for exit(). They were wrong in

all emulators.  These entries were unused, so the bug had no effect, but
the the args struct tag will be used to calculate sy_nargs correctly.

sys/i386/ibcs2/syscalls.master

@@ -32,7 +32,7 @@
 ; #ifdef's, etc. may be included, and are copied to the output files.
 
 0	NOPROTO	NOHIDE	{ int nosys(void); } syscall nosys_args int
-1	NOPROTO	NOHIDE	{ int exit(int rval); }
+1	NOPROTO	NOHIDE	{ void exit(int rval); } exit rexit_args void
 2	NOPROTO	POSIX	{ int fork(void); }
 3	STD	POSIX	{ int ibcs2_read(int fd, char *buf, u_int nbytes); }
 4	NOPROTO	POSIX	{ int write(int fd, char *buf, u_int nbytes); }