Fix compilation of test-delta
Fix compilation of test-delta

The code used write_in_full() without pulling its declarations from the
header file.  When header is included, usage[] collides with usage()
function.

Signed-off-by: Martin Koegler <ea56f0187842ce0af18f0283b5f003697482ffdd@auto.tuwien.ac.at>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

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