Fix expected error message

These are slightly changed as of PHP 8.0.0.

Author: cmb69

ext/standard/tests/dir/bug80960.phpt

@@ -15,12 +15,12 @@ opendir(str_pad("longname", PHP_MAXPATHLEN - strlen(getcwd()), "_"));
 --EXPECTF--
 Warning: opendir(notexist*): %s (code: 123) in %s on line %d
 
-Warning: opendir(notexist*): failed to open dir: No such file or directory in %s on line %d
+Warning: opendir(notexist*): Failed to open directory: No such file or directory in %s on line %d
 
 Warning: opendir(notexist?): %s (code: 123) in %s on line %d
 
-Warning: opendir(notexist?): failed to open dir: No such file or directory in %s on line %d
+Warning: opendir(notexist?): Failed to open directory: No such file or directory in %s on line %d
 
 Warning: opendir(longname%r_+%r): %s (code: 111) in %s on line %d
 
-Warning: opendir(longname%r_+%r): failed to open dir: Filename too long in %s on line %d
+Warning: opendir(longname%r_+%r): Failed to open directory: Filename too long in %s on line %d