Don't return file names with backslashes from search-path

[Eli Zaretskii]

This small patch plugs yet another hole through which Guile on Windows
could generate file names with backslashes.

OK to commit?

--- libguile/load.c~2   2014-07-03 09:58:29 +0300
+++ libguile/load.c     2014-08-14 17:28:26 +0300
@@ -657,7 +657,8 @@ search_path (SCM path, SCM filename, SCM
          if (stat (buf.buf, stat_buf) == 0
              && ! (stat_buf->st_mode & S_IFDIR))
            {
-             result = scm_from_locale_string (buf.buf);
+             result =
+               scm_from_locale_string (scm_i_mirror_backslashes (buf.buf));
              goto end;
            }
        }