selftests: timers: valid-adjtimex: build fix for newer toolchains

[ Upstream commit 9a16297 ]

Toolchains with an include file 'sys/timex.h' based on 3.18 will have a
'clock_adjtime' definition added, so it can't be static in the code:

valid-adjtimex.c:43:12: error: static declaration of ‘clock_adjtime’ follows non-static declaration

Fixes: e03a58c ("kselftests: timers: Add adjtimex SETOFFSET validity tests")
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Acked-by: John Stultz <jstultz@google.com>
Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

tools/testing/selftests/timers/valid-adjtimex.c

@@ -40,7 +40,7 @@
 #define ADJ_SETOFFSET 0x0100
 
 #include <sys/syscall.h>
-static int clock_adjtime(clockid_t id, struct timex *tx)
+int clock_adjtime(clockid_t id, struct timex *tx)
 {
 	return syscall(__NR_clock_adjtime, id, tx);
 }