mkostemp64: clear flags, as mkostemp does
mkostemp64: clear flags, as mkostemp does

This should have been made in commit 9649721950 but was forgotten.

Signed-off-by: Carlos Santos <2a7442c298acc4a91d7194decf545dfc1c52d086@datacom.com.br>

wbx-github/uclibc-ng,kraj/uclibc-ng,wbx-github/uclibc-ng,wbx-github/uclibc-ng,kraj/uclibc-ng,wbx-github/uclibc-ng,kraj/uclibc-ng,kraj/uclibc-ng