Fix various issues noted by Coverity

libc/semaphore/sem_getvalue.c

@@ -77,7 +77,7 @@
 
 int nxsem_getvalue(FAR sem_t *sem, FAR int *sval)
 {
-  if (sem && sval)
+  if (sem != NULL && sval != NULL)
     {
       *sval = sem->semcount;
       return OK;

net/tcp/tcp_send_buffered.c

@@ -1174,7 +1174,7 @@ int psock_tcp_cansend(FAR struct socket *psock)
       return -ENOTCONN;
     }
 
-  if (tcp_wrbuffer_test())
+  if (tcp_wrbuffer_test() < 0)
     {
       return -EWOULDBLOCK;
     }

net/tcp/tcp_wrbuffer.c

@@ -211,8 +211,15 @@ void tcp_wrbuffer_release(FAR struct tcp_wrbuffer_s *wrb)
 int tcp_wrbuffer_test(void)
 {
   int val = 0;
-  nxsem_getvalue(&g_wrbuffer.sem, &val);
-  return val > 0 ? OK : ERROR;
+  int ret;
+
+  ret = nxsem_getvalue(&g_wrbuffer.sem, &val);
+  if (ret >= 0)
+    {
+      ret = val > 0 ? OK : -ENOSPC;
+    }
+
+  return ret;
 }
 
 #endif /* CONFIG_NET && CONFIG_NET_TCP && CONFIG_NET_TCP_WRITE_BUFFERS */

sched/mqueue/mq_rcvinternal.c

@@ -302,7 +302,7 @@ ssize_t nxmq_do_receive(mqd_t mqdes, FAR struct mqueue_msg_s *mqmsg,
        * time the task is unblocked
        */
 
-      DEBUGASSERT(btcb);
+      DEBUGASSERT(btcb != NULL);
 
       btcb->msgwaitq = NULL;
       msgq->nwaitnotfull--;

sched/pthread/pthread_getschedparam.c

@@ -108,7 +108,8 @@ int pthread_getschedparam(pthread_t thread, FAR int *policy,
         {
           ret = -ret;
         }
-
+      else
+        {
           /* Get the scheduler policy. */
 
           ret = nxsched_getscheduler((pid_t)thread);
@@ -122,6 +123,7 @@ int pthread_getschedparam(pthread_t thread, FAR int *policy,
               ret = OK;
             }
         }
+    }
 
   sinfo("Returning %d\n", ret);
   return ret;

sched/pthread/pthread_mutexconsistent.c

@@ -153,10 +153,10 @@ int pthread_mutex_consistent(FAR pthread_mutex_t *mutex)
 #ifdef CONFIG_PTHREAD_MUTEX_TYPES
           mutex->nlocks = 0;
 #endif
+          ret = OK;
         }
 
       sched_unlock();
-      ret = OK;
     }
 
   sinfo("Returning %d\n", ret);

sched/sched/sched_setscheduler.c

@@ -141,6 +141,7 @@ int nxsched_setscheduler(pid_t pid, int policy,
     {
       default:
         DEBUGPANIC();
+        break;
 
       case SCHED_FIFO:
         {

wireless/ieee802154/ieee802154_primitive.c

@@ -309,14 +309,19 @@ FAR struct ieee802154_primitive_s *ieee802154_primitive_allocate(void)
 
           /* Check if we allocated the primitive structure */
 
-          if (prim != NULL)
+          if (prim == NULL)
             {
-              /* Yes... remember that this primitive structure was dynamically allocated */
+              /* No..  memory not available */
+
+              wlerr("ERROR: Failed to allocate primitive.\n");
+              return NULL;
+            }
+
+          /* Remember that this primitive structure was dynamically allocated */
 
           pool = POOL_PRIMITIVE_DYNAMIC;
         }
     }
-    }
 
   /* We have successfully allocated memory from some source.
    * Zero and tag the alloated primitive structure.