branch: group related arguments of create_branch()

branch: group related arguments of create_branch()

39bd6f726 (Allow checkout -B <current-branch> to update the current
branch, 2011-11-26) added 'clobber_head' (now, 'clobber_head_ok')
"before" 'track' as 'track' was closely related 'clobber_head' for
the purpose the commit wanted to achieve. Looking from the perspective
of how the arguments are used it turns out that 'clobber_head' is
more related to 'force' than it is to 'track'.

So, re-order the arguments to keep the related arguments close
to each other.

Signed-off-by: Kaartic Sivaraam <kaartic.sivaraam@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>