media: s5p-mfc: Remove firmware buf null check in s5p_mfc_load_firmware()

s5p_mfc_load_firmware() will not get called if fw_buf.virt allocation
fails. The allocation happens very early on in the probe routine and
probe fails if allocation fails.

There is no need to check if it is null in s5p_mfc_load_firmware().
Remove the check.

Signed-off-by: Shuah Khan <shuahkh@osg.samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>