tests: posix: common: clock: remove poorly conditioned tests

The test assumed initial equality between CLOCK_MONOTONIC and
CLOCK_REALTIME and also assumed coarse granularity for each clock.
Neither of those assumptions are solid.

Furthermore, the test failed on multiple vendor boards which caused
some concern.

Remove the poorly conditioned tests and remove some comments
/ printks.

Fixes #35703

Signed-off-by: Christopher Friedt <[email protected]>

Author: cfriedt

tests/posix/common/src/clock.c

@@ -46,34 +46,16 @@ void test_posix_clock(void)
 
 void test_posix_realtime(void)
 {
-	/* Make sure the realtime and monotonic clocks start out the
-	 * same.  This is not true on posix and where there is a
-	 * realtime clock, so don't keep this code.
-	 */
-
 	int ret;
 	struct timespec rts, mts;
 	struct timeval tv;
 
-	printk("POSIX clock set APIs\n");
-
-	/* Minimal sleep to align us to the next tick interval. This
-	 * helps with a case that 2 consecutive calls to clock_gettime()
-	 * below return different values. Note that the tick alignment
-	 * approach may break, in which case follow the suggestion in the
-	 * comment above.
-	 */
-	k_usleep(1);
-
 	ret = clock_gettime(CLOCK_MONOTONIC, &mts);
 	zassert_equal(ret, 0, "Fail to get monotonic clock");
 
 	ret = clock_gettime(CLOCK_REALTIME, &rts);
 	zassert_equal(ret, 0, "Fail to get realtime clock");
 
-	zassert_equal(rts.tv_sec, mts.tv_sec, "Seconds not equal");
-	zassert_equal(rts.tv_nsec, mts.tv_nsec, "Nanoseconds not equal");
-
 	/* Set a particular time.  In this case, the output of:
 	 * `date +%s -d 2018-01-01T15:45:01Z`
 	 */
@@ -141,6 +123,4 @@ void test_posix_realtime(void)
 			" provide correct result");
 	zassert_true(rts.tv_nsec >= tv.tv_usec * NSEC_PER_USEC,
 			"gettimeofday didn't provide correct result");
-
-	printk("POSIX clock set APIs test done\n");
 }