[ruby-cvs:69777] hsbt:r62611 (trunk): Prefer to use %x instead of backtick.

[hsbt at ruby-lang.org]

hsbt	2018-02-28 20:12:36 +0900 (Wed, 28 Feb 2018)

  New Revision: 62611

  https://svn.ruby-lang.org/cgi-bin/viewvc.cgi?view=revision&revision=62611

  Log:
    Prefer to use %x instead of backtick.

  Modified files:
    trunk/tool/make-snapshot