Rename the local definition of LIST_HEAD to BSD_LIST_HEAD. This fixes a
ctags error if we apply the C rules to header files  as well:

ctags: Warning: drivers/scsi/aic7xxx/aic79xx.h:1072: null expansion of name pattern "\3"
ctags: Warning: drivers/scsi/aic7xxx/aic7xxx.h:919: null expansion of name pattern "\3"

Signed-off-by: Michal Marek <mmarek@suse.com>