ip_watcher: Rename DEV_NAME_LEN definition
ip_watcher: Rename DEV_NAME_LEN definition

The term 'len' only represents the number of characters in a string,
as opposed to 'size' which means the number of bytes including the
terminating null byte ('\0').
DEV_NAME_LEN is defined as IFNAMSIZ, so we are clearly interested in the
size. Rename to DEV_NAME_SIZE to make this more clear.

Signed-off-by: Jan Höppner <96138615ab4af0813785fa10d283f3d37eca3b78@linux.ibm.com>

ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools,ibm-s390-tools/s390-tools