sh_setmatch(): fix node size calculation

This fixes the function that sets ${.sh.match}. Patch from OpenSUSE:
https://build.opensuse.org/package/view_file/shells/ksh/ksh93-limit-name-len.dif

src/cmd/ksh93/sh/init.c: sh_setmatch():
- Fix node size calculation, possibly preventing data corruption.

src/cmd/ksh93/include/ulimit.h: Limit_t:
- Defining the 'name' struct member as 'char name[16]' makes
  no sense as the name is being initialised statically in
  data/limits.c; just make it a 'char *name' pointer.

src/cmd/ksh93/include/ulimit.h

@@ -157,7 +157,7 @@
 
 typedef struct Limit_s
 {
-	const char	name[16];
+	const char*	name;
 	const char*	description;
 	int		index;
 	const char*	conf;