The patch, acfab373 - Handle upper case MAC addresses in ifname 
option,takes care of only the MAC conversion to lower case in the 
interface name.  But the same has to be taken care for BOOTIF also.  
This patch takes care of changing the BOOTIF to lower case.

Note that sed has been used in the patch instead of tr, as it is not 
compulsion to install tr by dracut in the initramfs and may not be 
available always.

Signed-off-by: Srinivasa T N (seenutn-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org)