USB: gadget: Return -ENOMEM on memory allocation failure

In this code, 0 is returned on memory allocation failure, even though other
failures return -ENOMEM or other similar values.

A simplified version of the semantic match that finds this problem is as
follows: (http://coccinelle.lip6.fr/)

// <smpl>
@@
expression ret;
expression x,e1,e2,e3;
@@

ret = 0
... when != ret = e1
*x = \(kmalloc\|kcalloc\|kzalloc\)(...)
... when != ret = e2
if (x == NULL) { ... when != ret = e3
  return ret;
}
// </smpl>
Signed-off-by: NJulia Lawall <julia@diku.dk>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/gadget/m66592-udc.c

@@ -1609,6 +1609,7 @@ static int __init m66592_probe(struct platform_device *pdev)
 	/* initialize ucd */
 	m66592 = kzalloc(sizeof(struct m66592), GFP_KERNEL);
 	if (m66592 == NULL) {
+		ret = -ENOMEM;
 		pr_err("kzalloc error\n");
 		goto clean_up;
 	}