[media] staging: lirc_zilog: Clean up tests if NULL returned on failure

Some functions like kmalloc/kzalloc return NULL on failure.
When NULL represents failure, !x is commonly used.

This was done using Coccinelle:
@@
expression *e;
identifier l1;
@@

e = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\)(...);
...
- e == NULL
+ !e

Signed-off-by: simran singhal <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/staging/media/lirc/lirc_zilog.c

···
 	ir = get_ir_device_by_adapter(adap);
 	if (ir == NULL) {
 		ir = kzalloc(sizeof(struct IR), GFP_KERNEL);
-		if (ir == NULL) {
+		if (!ir) {
 			ret = -ENOMEM;
 			goto out_no_ir;
 		}
···
 
 		/* Set up a struct IR_tx instance */
 		tx = kzalloc(sizeof(struct IR_tx), GFP_KERNEL);
-		if (tx == NULL) {
+		if (!tx) {
 			ret = -ENOMEM;
 			goto out_put_xx;
 		}
···
 
 		/* Set up a struct IR_rx instance */
 		rx = kzalloc(sizeof(struct IR_rx), GFP_KERNEL);
-		if (rx == NULL) {
+		if (!rx) {
 			ret = -ENOMEM;
 			goto out_put_xx;
 		}