media: gspca: drop unexpected word 'is' in the comments

there is an unexpected word 'is' in the comments that need to be dropped

file - drivers/media/usb/gspca/spca501.c
line - 491

* This is is for the 3com HomeConnect Lite which is spca501a based.

changed to:

* This is for the 3com HomeConnect Lite which is spca501a based.

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>