[v1.1] cd: avoid brackets in system error messages

The brackets in 'cd' errors have always slightly annoyed me:

    $ cd nonexistent
    -ksh: cd: nonexistent: [No such file or directory]

After this commit, this looks more like other shells:

    $ cd nonexistent
    -ksh: cd: nonexistent: No such file or directory

src/cmd/ksh93/bltins/cd_pwd.c: b_cd():
- To avoid errormsg() automatically adding the system error message
  within brackets, use ERROR_exit instead of ERROR_system.
- Manually add the system error using strerror(errno) instead.

This is not backported to 1.0 because it's not unheard of to grep
error messages in script output, so it could be an incompatibility.

Author: McDutchie

NEWS

@@ -14,6 +14,8 @@ Uppercase BUG_* IDs are shell bug IDs as used by the Modernish shell library.
   - correctly recognise a word that is quoted with the $'...' syntax,
     even when it includes a backslash-escaped single quote.
 
+- [v1.1] The 'cd' command no longer adds brackets to system error messages.
+
 2025-03-24:
 
 - Fixed a crash that occurred in specific circumstances when processing a

src/cmd/ksh93/bltins/cd_pwd.c

@@ -260,7 +260,7 @@ int	b_cd(int argc, char *argv[],Shbltin_t *context)
 	{
 		if(saverrno)
 			errno = saverrno;
-		errormsg(SH_DICT,ERROR_system(ret),"%s:",dir);
+		errormsg(SH_DICT,ERROR_exit(ret),"%s: %s",dir,strerror(errno));
 		UNREACHABLE();
 	}
 success:
@@ -272,7 +272,7 @@ int	b_cd(int argc, char *argv[],Shbltin_t *context)
 		if (!(dir=pathcanon(dir,PATH_PHYSICAL)))
 		{
 			dir = stkptr(sh.stk,PATH_OFFSET);
-			errormsg(SH_DICT,ERROR_system(ret),"%s:",dir);
+			errormsg(SH_DICT,ERROR_exit(ret),"%s: %s",dir,strerror(errno));
 			UNREACHABLE();
 		}
 		stkseek(sh.stk,dir-stkptr(sh.stk,0));