bedbug_860.c, bedbug_603e.c: Fix return type to silence compile warnings.

commit 47e26b1b "cmd_usage(): simplify return code handling" caused
the following compile warnings:

bedbug_860.c: In function 'bedbug860_do_break':
bedbug_860.c:73: warning: 'return' with a value, in function returning void
bedbug_860.c:121: warning: 'return' with a value, in function returning void

Fix the return type.

Actually these files could need some cleanup - commands should
return proper error codes, and there are coding style issues.
=> To be fixed later.

Signed-off-by: Wolfgang Denk <wd@denx.de>