Fixed common symbol in btl/usnic

- This commit fixes the accidental common symbol btl_usnic_lock
- It also moves the btl_usnic_lock declaration to btl_usnic.h

opal/mca/btl/usnic/btl_usnic.h

@@ -63,6 +63,10 @@ BEGIN_C_DECLS
  * at other times as needed or as tuning dictates.
  */
 extern uint64_t opal_btl_usnic_ticks;
+
+/* Lock for MPU_THREAD_MULTIPLE support */
+extern opal_recursive_mutex_t btl_usnic_lock;
+
 static inline uint64_t
 get_nsec(void)
 {

opal/mca/btl/usnic/btl_usnic_component.c

@@ -87,7 +87,7 @@
 #define OPAL_BTL_USNIC_NUM_COMPLETIONS 500
 
 /* MPI_THREAD_MULTIPLE_SUPPORT */
-opal_recursive_mutex_t btl_usnic_lock;
+opal_recursive_mutex_t btl_usnic_lock =  OPAL_RECURSIVE_MUTEX_STATIC_INIT;
 
 /* RNG buffer definition */
 opal_rng_buff_t opal_btl_usnic_rand_buff = {0};

opal/mca/btl/usnic/btl_usnic_module.h

@@ -53,12 +53,6 @@
 
 BEGIN_C_DECLS
 
-/*
- * MPI_THREAD_MULTIPLE support
- */
-extern opal_recursive_mutex_t btl_usnic_lock;
-
-
 /*
  * Forward declarations to avoid include loops
  */