bash scripts: always use "read -r"
    
    upstream: fedora
    resolves: bz2003832
    conflict: none
    
    commit a416930706944828ae9bd8daf49be8ca998d3fcc
    Author: Kairui Song <kasong@redhat.com>
    Date:   Wed Aug 4 15:50:30 2021 +0800
    
        bash scripts: always use "read -r"
    
        This helps to strip spaces and avoid mangling backslashes:
    
        https://github.com/koalaman/shellcheck/wiki/SC2162
    
        Signed-off-by: Kairui Song <kasong@redhat.com>
        Acked-by: Philipp Rudo <prudo@redhat.com>
    
    Signed-off-by: Tao Liu <ltao@redhat.com>