kunit/usercopy: Disable u64 test on 32-bit SPARC

usercopy of 64 bit values does not work on 32-bit SPARC:

# usercopy_test_valid: EXPECTATION FAILED at lib/tests/usercopy_kunit.c:209
Expected val_u64 == 0x5a5b5c5d6a6b6c6d, but
val_u64 == 1515936861 (0x5a5b5c5d)
0x5a5b5c5d6a6b6c6d == 6510899242581322861 (0x5a5b5c5d6a6b6c6d)

Disable the test.

Fixes: 4c5d7bc63775 ("usercopy: Add tests for all get_user() sizes")
Signed-off-by: Thomas Weißschuh <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Kees Cook <[e-mail]>

lib/tests/usercopy_kunit.c

···
 			    !defined(CONFIG_MICROBLAZE) &&	\
 			    !defined(CONFIG_NIOS2) &&		\
 			    !defined(CONFIG_PPC32) &&		\
+			    !defined(CONFIG_SPARC32) &&		\
 			    !defined(CONFIG_SUPERH))
 # define TEST_U64
 #endif