kernel: remove event_t as it suffered from a lost wakeup issue

kernel-src/include/event.h

@@ -1,12 +0,0 @@
-#ifndef _EVENT_H
-#define _EVENT_H
-
-#include <semaphore.h>
-typedef semaphore_t event_t;
-
-int event_wait(event_t *event, bool interruptible);
-void event_signal(event_t *event);
-
-#define EVENT_INIT(x) SEMAPHORE_INIT(x, 0);
-
-#endif

kernel-src/include/kernel/net.h

@@ -6,7 +6,6 @@
 
 #include <hashtable.h>
 #include <mutex.h>
-#include <event.h>
 #include <string.h>
 #include <arch/cpu.h>
 #include <kernel/abi.h>

kernel-src/include/kernel/pipefs.h

@@ -4,7 +4,6 @@
 #include <kernel/vfs.h>
 #include <ringbuffer.h>
 #include <semaphore.h>
-#include <event.h>
 #include <kernel/poll.h>
 
 typedef struct pipenode_t {