branch: don't fail listing branches if one of the commits wasn't found
branch: don't fail listing branches if one of the commits wasn't found

When listing branches with ref lookups, if one of the known raw refs
doesn't point to a commit then "git branch" would return error(),
terminating the whole for_each_rawref() iteration and possibly hiding
any remaining refs.

Signed-off-by: Simo Melenius <5587243fc3a33d64c55fab7d15a669b01e018920@iki.fi>
Reviewed-by: Jonathan Nieder <b57189c5f2fd5b3daf3350a77fde90def1080fa5@gmail.com>
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