IB/qib: Fix error return code in qib_init_7322_variables()

Convert a 0 error return code to a negative one, as returned elsewhere
in the function.

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

// <smpl>
@@
identifier ret;
expression e,e1,e2,e3,e4,x;
@@

(
if (\(ret != 0\|ret < 0\) || ...) { ... return ...; }
|
ret = 0
)
... when != ret = e1
*x = \(kmalloc\|kzalloc\|kcalloc\|devm_kzalloc\|ioremap\|ioremap_nocache\|devm_ioremap\|devm_ioremap_nocache\)(...);
... when != x = e2
    when != ret = e3
*if (x == NULL || ...)
{
  ... when != ret = e4
*  return ret;
}
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Acked-by: Mike Marciniszyn <mike.marciniszyn@intel.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>

drivers/infiniband/hw/qib/qib_iba7322.c

@@ -6346,8 +6346,10 @@ static int qib_init_7322_variables(struct qib_devdata *dd)
 			dd->piobcnt4k * dd->align4k;
 		dd->piovl15base	= ioremap_nocache(vl15off,
 						  NUM_VL15_BUFS * dd->align4k);
-		if (!dd->piovl15base)
+		if (!dd->piovl15base) {
+			ret = -ENOMEM;
 			goto bail;
+		}
 	}
 	qib_7322_set_baseaddrs(dd); /* set chip access pointers now */