bus-message: avoid wrap-around when using length read from message
    
    We would read (-1), and then add 1 to it, call message_peek_body(..., 0, ...),
    and when trying to make use of the data.
    
    The fuzzer test case is just for one site, but they all look similar.
    
    v2: fix two UINT8_MAX/UINT32_MAX mismatches founds by LGTM
    (cherry picked from commit 902000c19830f5e5a96e8948d691b42e91ecb1e7)
    
    Resolves: #1696224
    
    patch_name: 0176-bus-message-avoid-wrap-around-when-using-length-read.patch
    present_in_specfile: true
    location_in_specfile: 176
    squash_commits: true