tst_test: Print used temporary dir and its filesystem

It helps debugging to know used filesystem (and in case of
TST_ALL_FILESYSTEMS=1 the underlying filesystem). This follows
5cabf2b change in C API, using 'stat' which should work also on
busybox.

Missing 'stat' binary (or busybox symlink) does not break test (just the
output is mangled), thus 'stat' presence is not tested/required.

Link: https://lore.kernel.org/ltp/20240726095546.1041726-4-pvorel@suse.cz/
Reviewed-by: Avinesh Kumar <akumar@suse.de>
Signed-off-by: Petr Vorel <pvorel@suse.cz>

testcases/lib/tst_test.sh

@@ -745,6 +745,7 @@ tst_run()
 
 		TST_STARTWD=$(pwd)
 		cd "$TST_TMPDIR"
+		tst_res TINFO "Using $TST_TMPDIR as tmpdir ($(stat -f -c '%T' $TST_TMPDIR) filesystem)"
 	fi
 
 	# needs to be after cd $TST_TMPDIR to keep test_dev.img under $TST_TMPDIR