clvmd: fix valgrind warning

clvmd: fix valgrind warning

Initialize mutex upfront any debugging and fix this report:

Mutex reinitialization: mutex 0x485d20, recursion count 0, owner 1.
   at 0x4C38480: pthread_mutex_init_intercept (drd_pthread_intercepts.c:821)
   by 0x4C38480: pthread_mutex_init (drd_pthread_intercepts.c:830)
   by 0x11F359: main (clvmd.c:562)
mutex 0x485d20 was first observed at:
   at 0x4C38F63: pthread_mutex_lock_intercept (drd_pthread_intercepts.c:885)
   by 0x4C38F63: pthread_mutex_lock (drd_pthread_intercepts.c:898)
   by 0x11E920: debuglog (clvmd.c:254)
   by 0x11F1D8: main (clvmd.c:527)