Ticket #47890 - minor memory leaks in utilities
    
    Description:
    tools/rsearch/nametable.c - if nt_push fails and the strdup'ed
                                string is not pushed to the table,
                                free the string.
    tools/migratecred.c - free strdup'ed strings oldpath, newpath,
                          prefixCred, and pluginpath at the end of
                          the process.
    
    https://fedorahosted.org/389/ticket/47890
    
    Reviewed by mreynolds@redhat.com (Thank you, Mark!!)
    
    (cherry picked from commit 1279f0e0fe1d0f5456e42ef5b7a9f395f793cc9e)