This patch marks the function ahci_init_interrupts() as static in ahci.c
because it is not used outside this file.

Thus, it also eliminates the following warning in ahci.c:
drivers/ata/ahci.c:1099:5: warning: no previous prototype for ‘ahci_init_interrupts’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Signed-off-by: NTejun Heo <tj@kernel.org>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>