time: Correct the prototype of ns_to_kernel_old_timeval and ns_to_timespec64

In ns_to_kernel_old_timeval() definition, the function argument is defined
with const identifier in kernel/time/time.c, but the prototype in
include/linux/time32.h looks different.

- The function is defined in kernel/time/time.c as below:
  struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)

- The function is decalared in include/linux/time32.h as below:
  extern struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec);

Because the variable of arithmethic types isn't modified in the calling scope,
there's no need to mark arguments as const, which was already mentioned during 
review (Link[1) of the original patch.

Likewise remove the "const" keyword in both definition and declaration of
ns_to_timespec64() as requested by Arnd (Link[2]).

Fixes: a84d116 ("y2038: Introduce struct __kernel_old_timeval")
Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/all/20220712094715.2918823-1-youngmin.nam@samsung.com
Link[1]: https://lore.kernel.org/all/20180310081123.thin6wphgk7tongy@gmail.com/
Link[2]: https://lore.kernel.org/all/CAK8P3a3nknJgEDESGdJH91jMj6R_xydFqWASd8r5BbesdvMBgA@mail.gmail.com/

Author: Youngmin Nam

include/linux/time64.h

@@ -145,7 +145,7 @@ static inline s64 timespec64_to_ns(const struct timespec64 *ts)
  *
  * Returns the timespec64 representation of the nsec parameter.
  */
-extern struct timespec64 ns_to_timespec64(const s64 nsec);
+extern struct timespec64 ns_to_timespec64(s64 nsec);
 
 /**
  * timespec64_add_ns - Adds nanoseconds to a timespec64

kernel/time/time.c

@@ -449,7 +449,7 @@ time64_t mktime64(const unsigned int year0, const unsigned int mon0,
 }
 EXPORT_SYMBOL(mktime64);
 
-struct __kernel_old_timeval ns_to_kernel_old_timeval(const s64 nsec)
+struct __kernel_old_timeval ns_to_kernel_old_timeval(s64 nsec)
 {
 	struct timespec64 ts = ns_to_timespec64(nsec);
 	struct __kernel_old_timeval tv;
@@ -503,7 +503,7 @@ EXPORT_SYMBOL(set_normalized_timespec64);
  *
  * Returns the timespec64 representation of the nsec parameter.
  */
-struct timespec64 ns_to_timespec64(const s64 nsec)
+struct timespec64 ns_to_timespec64(s64 nsec)
 {
 	struct timespec64 ts = { 0, 0 };
 	s32 rem;