make check configs updated to use relpath

tests/conf/modelnet-p2p-bw-loggp.conf

@@ -12,5 +12,5 @@ PARAMS
    packet_size="2147483648";
    message_size="128";
    modelnet="loggp";
-   net_config_file="tests/conf/ng-mpi-tukey.dat";
+   net_config_file="ng-mpi-tukey.dat";
 }

tests/conf/modelnet-test-loggp.conf

@@ -12,5 +12,5 @@ PARAMS
    packet_size="512";
    message_size="256";
    modelnet="loggp";
-   net_config_file="tests/conf/ng-mpi-tukey.dat";
+   net_config_file="ng-mpi-tukey.dat";
 }