usb: common: move function's kerneldoc next to its definition

usb: common: move function's kerneldoc next to its definition

[ Upstream commit 365038f24b3e9d2b7c9e499f03f432040e28a35c ]

Following a general rule, add the kerneldoc for a function next
to it's definition, but not next to its declaration in a header
file.

Suggested-by: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
Link: https://lore.kernel.org/r/c4d2e010ae2bf67cdfa0b55e6d1deb9339d9d3dc.1615170625.git.chunfeng.yun@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Stable-dep-of: b6155eaf6b05 ("usb: common: debug: Check non-standard control requests")
Signed-off-by: Sasha Levin <sashal@kernel.org>