nvmem: lan9662-otp: Change return type of lan9662_otp_wait_flag_clear()

The blamed commit introduced the following smatch warning in the
function lan9662_otp_wait_flag_clear:
drivers/nvmem/lan9662-otpc.c:43 lan9662_otp_wait_flag_clear() warn: signedness bug returning '(-110)'

Fix this by changing the return type of the function
lan9662_otp_wait_flag_clear() to be int instead of bool.

Fixes: 9e8f208 ("nvmem: lan9662-otp: add support")
Reported-by: kernel test robot <lkp@intel.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Horatiu Vultur <horatiu.vultur@microchip.com>
Signed-off-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org>
Link: https://lore.kernel.org/r/20221118063840.6357-5-srinivas.kandagatla@linaro.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/nvmem/lan9662-otpc.c

@@ -36,7 +36,7 @@ struct lan9662_otp {
 	void __iomem *base;
 };
 
-static bool lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag)
+static int lan9662_otp_wait_flag_clear(void __iomem *reg, u32 flag)
 {
 	u32 val;