trace.c: do not mark getnanotime() as "inline"

Oracle Studio compilers don't allow for static variables in
functions that are defined to be inline. GNU C does permit this.

Let's reference the C99 standard though, which doesn't allow for
inline functions to contain modifiable static variables.

Signed-off-by: Ben Walton <bdwalton@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

trace.c

@@ -384,7 +384,7 @@ static inline uint64_t gettimeofday_nanos(void)
  * Returns nanoseconds since the epoch (01/01/1970), for performance tracing
  * (i.e. favoring high precision over wall clock time accuracy).
  */
-inline uint64_t getnanotime(void)
+uint64_t getnanotime(void)
 {
 	static uint64_t offset;
 	if (offset > 1) {