name-rev: rewrite create_or_update_name()

name-rev: rewrite create_or_update_name()

This code was moved straight out of name_rev(). As such, we inherited
the "goto" to jump from an if into an else-if. We also inherited the
fact that "nothing to do -- return NULL" is handled last.

Rewrite the function to first handle the "nothing to do" case. Then we
can handle the conditional allocation early before going on to populate
the struct. No need for goto-ing.

Signed-off-by: Martin Ågren <redacted>
Signed-off-by: Junio C Hamano <redacted>