NFC: trf7970a: Don't return value from trf7970a_switch_rf_on()
NFC: trf7970a: Don't return value from trf7970a_switch_rf_on()

trf7970a_switch_rf_on() no longer returns anything other than 0 so make
it void and clean up the code that checks for errors when its called.

Signed-off-by: Mark A. Greer <2540a8c57225c2058d000de41debc8b502ea4a38@animalcreek.com>
Signed-off-by: Samuel Ortiz <0ba86cb3f08bbb861958e54bd3438887adb4263c@linux.intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs