drm/prime: drop unexpected word "the" in the comments

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

file: drivers/gpu/drm/drm_prime.c
line: 842
* of the the buffer described by the provided sg_table.
changed to
* of the buffer described by the provided sg_table.

Signed-off-by: Jiang Jian <jiangjian@cdjrlc.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220621130210.125461-1-jiangjian@cdjrlc.com