Looking at the call to the compiler in the config.log you will notice that “-lpbs” is not one of the arguments provided. It looks like the method used to check for tm_init() defined in config/orte_check_tm.m4 relies on a script called pbs-config being present. It uses this script to gather information like CPPFLAGS, LDFLAGS, and LIBS that are required for linking the library. I think the easiest approach would be to create a new version of pbs-config for PBS Pro, rather than attempt to change OpenMPI.
Are you able to file a ticket in our JIRA system? It is located here: https://pbspro.atlassian.net/secure/Dashboard.jspa