i2c: dev: don't start function name with 'return'

commit 72a71f869c95dc11b73f09fe18c593d4a0618c3f upstream.

I stumbled multiple times over 'return_i2c_dev', especially before the
actual 'return res'. It makes the code hard to read, so reanme the
function to 'put_i2c_dev' which also better matches 'get_free_i2c_dev'.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Change-Id: Ibdaa3c769a5bd38014f7bcfee5db299d9398f957