media: staging: media: Replace "cant" with "can't"

Replace "cant" with "can't".
"cant" is not same as "Can not" or "Can't".

Signed-off-by: Arushi Singhal <arushisinghal19971997@gmail.com>
Acked-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>