Don't include assert.h from public header file

Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>

sched/environ/env_clearenv.c

@@ -28,6 +28,8 @@
 
 #include <sched.h>
 #include <stdlib.h>
+#include <assert.h>
+
 #include "sched/sched.h"
 #include "environ/environ.h"
 

sched/environ/env_dup.c

@@ -29,6 +29,7 @@
 #include <sys/types.h>
 #include <sched.h>
 #include <string.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/kmalloc.h>

sched/environ/env_findvar.c

@@ -29,6 +29,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <sched.h>
+#include <assert.h>
 
 #include "environ/environ.h"
 

sched/environ/env_foreach.c

@@ -29,6 +29,7 @@
 #include <stdbool.h>
 #include <string.h>
 #include <sched.h>
+#include <assert.h>
 
 #include <nuttx/environ.h>
 

sched/environ/env_release.c

@@ -27,6 +27,7 @@
 #ifndef CONFIG_DISABLE_ENVIRON
 
 #include <sched.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/kmalloc.h>

sched/environ/env_removevar.c

@@ -28,6 +28,7 @@
 
 #include <string.h>
 #include <sched.h>
+#include <assert.h>
 
 #include "environ/environ.h"
 

sched/environ/env_setenv.c

@@ -30,6 +30,7 @@
 #include <stdlib.h>
 #include <sched.h>
 #include <string.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/kmalloc.h>

sched/environ/env_unsetenv.c

@@ -28,6 +28,7 @@
 
 #include <sched.h>
 #include <string.h>
+#include <assert.h>
 #include <errno.h>
 
 #include <nuttx/kmalloc.h>