enic: enic_main: fix sparse warnings

this patch fixes following sparse warnings:

enic_main.c:92:28: warning: symbol 'mod_table' was not declared. Should it be static?
enic_main.c:109:28: warning: symbol 'mod_range' was not declared. Should it be static?
enic_main.c:1306:5: warning: symbol 'enic_busy_poll' was not declared. Should it be static?

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>