clang fixes

NEXT_SIBLING is used in functions that return pointers, so returning false on error is misleading and relies on implicit conversion. Return (void *)0 instead to make the failure value explicit and match the surrounding function return type.

This is flagged by clang-22 due to Replacing return false with return (void *)0 avoids clang's -Wbool-conversion error when the macro expands inside functions returning a pointer type.

Signed-off-by: Khem Raj khem.raj@oss.qualcomm.com