EDAC/amd64: Simplify return statement in dct_ecc_enabled()

Simplify the return statement to improve the code's readability.

No functional changes.

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Reviewed-by: Yazen Ghannam <yazen.ghannam@amd.com>
Link: https://lore.kernel.org/r/20250201130953.1377-2-thorsten.blum@linux.dev