Remove kernel param "quiet" from kdump kernel cmdline
    
    "quiet" will disable most of log messages. For debugging kdump
    kernel purpose it is better to remove quiet in 2nd kernel so that
    we always see kernel messages.
    
    Signed-off-by: Dangyi Liu <dliu@redhat.com>
    Acked-by: Dave Young <dyoung@redhat.com>