ftrace: Simplify the dyn_ftrace->flags macro

All the three macro are defined to be used for ftrace_rec_count(). This
can be achieved by (flags & FTRACE_REF_MAX) directly.

Since no other places would use those macros, remove them for clarity.

Also it fixes a typo in the comment.

Link: https://lkml.kernel.org/r/20200831031104.23322-4-richard.weiyang@linux.alibaba.com

Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

include/linux/ftrace.h

@@ -432,7 +432,7 @@ bool is_ftrace_trampoline(unsigned long addr);
  *  DIRECT   - there is a direct function to call
  *
  * When a new ftrace_ops is registered and wants a function to save
- * pt_regs, the rec->flag REGS is set. When the function has been
+ * pt_regs, the rec->flags REGS is set. When the function has been
  * set up to save regs, the REG_EN flag is set. Once a function
  * starts saving regs it will do so until all ftrace_ops are removed
  * from tracing that function.
@@ -450,12 +450,9 @@ enum {
 };
 
 #define FTRACE_REF_MAX_SHIFT	23
-#define FTRACE_FL_BITS		9
-#define FTRACE_FL_MASKED_BITS	((1UL << FTRACE_FL_BITS) - 1)
-#define FTRACE_FL_MASK		(FTRACE_FL_MASKED_BITS << FTRACE_REF_MAX_SHIFT)
 #define FTRACE_REF_MAX		((1UL << FTRACE_REF_MAX_SHIFT) - 1)
 
-#define ftrace_rec_count(rec)	((rec)->flags & ~FTRACE_FL_MASK)
+#define ftrace_rec_count(rec)	((rec)->flags & FTRACE_REF_MAX)
 
 struct dyn_ftrace {
 	unsigned long		ip; /* address of mcount call-site */