kunit/overflow: fix UB in overflow_allocation_test

kunit/overflow: fix UB in overflow_allocation_test

The 'device_name' array doesn't exist out of the
'overflow_allocation_test' function scope.  However, it is being used
as a driver name when calling 'kunit_driver_create' from
'kunit_device_register'.  It produces the kernel panic with KASAN
enabled due to undefined behaviour.

Since this variable is used in one place only, remove it and pass the
device name into kunit_device_register directly as an ascii string.

Link: https://lkml.kernel.org/r/20240815000431.401869-1-ivan.orlov0322@gmail.com
Fixes: ca90800a91ba ("test_overflow: Add memory allocation overflow tests")
Signed-off-by: Ivan Orlov <ivan.orlov0322@gmail.com>
Tested-by: Erhard Furtner <erhard_f@mailbox.org>
Reviewed-by: David Gow <davidgow@google.com>
Cc: Kees Cook <kees@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>