clk: clocking-wizard: Fix Oops in clk_wzrd_register_divider()

clk: clocking-wizard: Fix Oops in clk_wzrd_register_divider()

Smatch detected this potential error pointer dereference
clk_wzrd_register_divider().  If devm_clk_hw_register() fails then
it sets "hw" to an error pointer and then dereferences it on the
next line.  Return the error directly instead.

Fixes: 5a853722eb32 ("staging: clocking-wizard: Add support for dynamic reconfiguration")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Link: https://lore.kernel.org/r/f0e39b5c-4554-41e0-80d9-54ca3fabd060@kili.mountain
Reviewed-by: Michal Simek <michal.simek@amd.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>