fix broken syntax in bash completion
    
    The completion code added in f7d9b56 ("Port fedrepo-req and
    fedrepo-req-branch to fedpkg", 2017-12-07) missed ';;' separating the
    request-branch and request-repo patterns.  Attempting to source the
    bash completion script results in an error:
    
    $ . /usr/share/bash-completion/completions/fedpkg.bash
    -bash: /usr/share/bash-completion/completions/fedpkg.bash: line 196: syntax error near unexpected token `)'
    -bash: /usr/share/bash-completion/completions/fedpkg.bash: line 196: `        request-repo)'
    
    Signed-off-by: Todd Zullinger <tmz@pobox.com>