devtools: make checkpatch cleaner for renamed files
devtools: make checkpatch cleaner for renamed files

When a file is renamed, a normal diff will include all the code of
the renamed file, and checkpatch will find warnings and errors,
even though it's just a rename.

This change will result in a 'rename' line in the diff, resulting
in a much cleaner checkpatches result.

Signed-off-by: David Hunt <763be7c8e0ad91e03160e7aed76d5cd41534e2f9@intel.com>
Acked-by: Bruce Richardson <66b9e8e8fbd5e9f41f91b0af050876182ce9d0e4@intel.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk