cmd: rename *.C to *.c These were *.C back in 2003, before the 9 script, to avoid conflicts with the system utilities. A later change renamed them, but that change seems to have been lost during the hg->git conversion because I ran the conversion on a case-insensitive file system. Change-Id: Id32c99cb9571ef0e185c3cc9e8c8d6d5b48ca195