NFC: st21nfca: Drop two useless checks in ACPI probe path

When st21nfca_hci_i2c_acpi_request_resources() gets called we
already know that the entries in ->acpi_match_table have matched
ACPI ID of the device.
In addition I2C client pointer cannot be NULL in any case
(otherwise I2C core would not call ->probe() for the driver in
the first place).

Drop the two useless checks from the driver.

Signed-off-by: Christophe Ricard <christophe-h.ricard@st.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>