test: posix: timers: Fix unused function warning

Building with clang warns:

tests/posix/timers/src/clock.c:37:20: error: unused function 'tv_to_ts'
[-Werror,-Wunused-function]
static inline void tv_to_ts(const struct timeval *tv, struct timespec *ts)
                   ^
tests/posix/timers/src/clock.c:51:16: error: unused function 'tp_eq'
[-Werror,-Wunused-function]
_decl_op(bool, tp_eq, ==);     /* a == b */
               ^
tests/posix/timers/src/clock.c:52:16: error: unused function 'tp_lt'
[-Werror,-Wunused-function]
_decl_op(bool, tp_lt, <);      /* a < b */
               ^
tests/posix/timers/src/clock.c:53:16: error: unused function 'tp_gt'
[-Werror,-Wunused-function]
_decl_op(bool, tp_gt, >);      /* a > b */
               ^
tests/posix/timers/src/clock.c:54:16: error: unused function 'tp_le'
[-Werror,-Wunused-function]
_decl_op(bool, tp_le, <=);     /* a <= b */

tests/posix/timers/src/clock.c:59:20: error: unused function
'tp_diff_in_range_ns' [-Werror,-Wunused-function]
static inline bool tp_diff_in_range_ns(const struct timespec *a,
                   ^                   const struct timespec *b,

tests/posix/timers/src/clock.c:49:20: error: unused function
'tp_diff_in_range_ns' [-Werror,-Wunused-function]
static inline bool tp_diff_in_range_ns(const struct timespec *a,
                   ^                   const struct timespec *b,

Signed-off-by: Tom Hughes <tomhughes@chromium.org>

Author: thughes

tests/posix/timers/src/clock.c

@@ -34,16 +34,10 @@ static inline int64_t ts_to_ns(const struct timespec *ts)
 	return ts->tv_sec * NSEC_PER_SEC + ts->tv_nsec;
 }
 
-static inline void tv_to_ts(const struct timeval *tv, struct timespec *ts)
-{
-	ts->tv_sec = tv->tv_sec;
-	ts->tv_nsec = tv->tv_usec * NSEC_PER_USEC;
-}
-
 #define _tp_op(_a, _b, _op) (ts_to_ns(_a) _op ts_to_ns(_b))
 
 #define _decl_op(_type, _name, _op)                                                                \
-	static inline _type _name(const struct timespec *_a, const struct timespec *_b)            \
+	__used static inline _type _name(const struct timespec *_a, const struct timespec *_b)     \
 	{                                                                                          \
 		return _tp_op(_a, _b, _op);                                                        \
 	}
@@ -56,8 +50,8 @@ _decl_op(bool, tp_ge, >=);     /* a >= b */
 _decl_op(int64_t, tp_diff, -); /* a - b */
 
 /* lo <= (a - b) < hi */
-static inline bool tp_diff_in_range_ns(const struct timespec *a, const struct timespec *b,
-				       int64_t lo, int64_t hi)
+__used static inline bool tp_diff_in_range_ns(const struct timespec *a, const struct timespec *b,
+					      int64_t lo, int64_t hi)
 {
 	int64_t diff = tp_diff(a, b);