media: atomisp: make atomisp_css_continuous_set_num_raw_frames() void

media: atomisp: make atomisp_css_continuous_set_num_raw_frames() void

The return value of atomisp_css_continuous_set_num_raw_frames() function
is always 0, so there's no reason for a return value. In addition, the
__enable_continuous_mode() checked the return value for possible error
which is unnecessary. Convert atomisp_css_continuous_set_num_raw_frames()
to a void function.

Link: https://lore.kernel.org/linux-media/1605362150-11401-1-git-send-email-kaixuxia@tencent.com
Reported-by: Tosk Robot <tencent_os_robot@tencent.com>
Signed-off-by: Kaixu Xia <kaixuxia@tencent.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>