commit: factor status configuration is a helper function
commit: factor status configuration is a helper function

cmd_commit and cmd_status use very similar code to initialize the
wt_status structure. Factor this code into a function to ensure future
changes will keep both versions consistent.

Signed-off-by: Matthieu Moy <d4d2cc2a6ec7b2aa587d4887cc5ed200f9b685a1@imag.fr>
Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git