Fix potential memory leak on error

In osdThread.c for POSIX if pthread_create_key fails
In iocLogServer.c if fdmgr_init returns NULL
In dbBkpt.c if semaphore creation fails while adding a bp to a lockset
In devSiSoftCallback.c if linked record is not found

modules/database/src/ioc/db/dbBkpt.c

@@ -331,6 +331,7 @@ long dbb(const char *record_name)
      if (pnode->ex_sem == NULL) {
         printf("   BKPT> Out of memory\n");
         dbScanUnlock(precord);
+        free(pnode);
         epicsMutexUnlock(bkpt_stack_sem);
         return(1);
      }

modules/database/src/std/dev/devSiSoftCallback.c

@@ -108,6 +108,7 @@ static long add_record(dbCommon *pcommon)
 
         recGblRecordError(status, (void *)prec,
             "devSiSoftCallback (add_record) linked record not found");
+        free(pdevPvt);
         return status;
     }