Checks to see if any of the specified drivers have been initialized. Function tests a space-delimited list of driver names to see how many of the given drivers have been initialized, and how often. The return code of the function is: 0 if no matching drivers were found to have been initialized; -1 if an error occurred allocating the internal buffer; or, a positive number indicating the number of streams encountered that belong to drivers on the provided list. This function invokes plP_getinitdriverlist internally to get a complete list of drivers that have been initialized in order to compare with the driver names specified in the argument list to plP_checkdriverinit.