i2c: remove redundant error print in stm32f7_i2c_probe

Coccinelle reports a redundant error print in stm32f7_i2c_probe.
As 'platform_get_irq' already prints the error message, error
print here is redundant and can be removed.

Signed-off-by: Menglong Dong <dong.menglong@zte.com.cn>
Signed-off-by: Wolfram Sang <wsa@kernel.org>