seqlock: Fix struct name and constants.

This commit fixed struct name and constant.

Signed-off-by: ouyangxiangzhen <ouyangxiangzhen@xiaomi.com>

include/nuttx/seqlock.h

@@ -93,7 +93,7 @@ uint32_t read_seqbegin(FAR const seqcount_t *s)
   uint32_t seq;
 
 #ifdef CONFIG_SMP
-  seq = atomic_read_acquire((FAR atomic_t *)&s->sequence) & ~1;
+  seq = atomic_read_acquire((FAR atomic_t *)&s->sequence) & (~1u);
 #else
   seq = s->sequence;
   SMP_RMB();

include/nuttx/spinlock_type.h

@@ -98,7 +98,7 @@ typedef union rspinlock_u
 
 #define SEQLOCK_INITIALIZER { 0u }
 
-typedef struct seqclock
+typedef struct seqcount_s
 {
   uint32_t sequence;
 } seqcount_t;