NFC: set info->ram_patch to NULL when it is released

When info->ram_patch is released info->otp_patch is being set
to NULL rather than info->ram_patch. I believe this is a cut-n-paste
bug from almost identical code proceeding it that uses the same
idiom for info->otp_patch.
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>

drivers/nfc/fdp/fdp.c

@@ -345,7 +345,7 @@ static void fdp_nci_release_firmware(struct nci_dev *ndev)
 
 	if (info->ram_patch) {
 		release_firmware(info->ram_patch);
-		info->otp_patch = NULL;
+		info->ram_patch = NULL;
 	}
 }