fix preprocessor condition

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45739 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
new macros for statfs_t

* file.c (HAVE_STRUCT_STATFS_T_F_FSTYPENAME): Add new macro for
  statfs_t.
* file.c (HAVE_STRUCT_STATFS_T_F_TYPE): ditto.

* file.c (rb_io_statfs): check FSTATFS macro only instead of
  HAVE_FSTATFS and HAVE_FSTATVFS.

* file.c (statfs_type): use new macro.
* file.c (statfs_fstypename): ditto.
* file.c (statfs_inspect): ditto.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45740 b2dd03c8-39d4-4d8f-98ff-823fe69b080e