IB/ehca: handle negative return value from ibmebus_request_irq() properly

ehca_create_eq() was assigning a signed return value to an unsiged
local variable and then checking if the variable was < 0, which meant
that errors were always ignored.  Fix this by using one variable for
signed integer return values and another for u64 hcall return values.

Bug originally found by Roel Kluin <12o3l@tiscali.nl>.
Signed-off-by: Hoang-Nam Nguyen <hnguyen@de.ibm.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ehca/ehca_eq.c

@@ -54,7 +54,8 @@ int ehca_create_eq(struct ehca_shca *shca,
 		   struct ehca_eq *eq,
 		   const enum ehca_eq_type type, const u32 length)
 {
-	u64 ret;
+	int ret;
+	u64 h_ret;
 	u32 nr_pages;
 	u32 i;
 	void *vpage;
@@ -73,7 +74,7 @@ int ehca_create_eq(struct ehca_shca *shca,
 		return -EINVAL;
 	}
 
-	ret = hipz_h_alloc_resource_eq(shca->ipz_hca_handle,
+	h_ret = hipz_h_alloc_resource_eq(shca->ipz_hca_handle,
 					 &eq->pf,
 					 type,
 					 length,
@@ -81,7 +82,7 @@ int ehca_create_eq(struct ehca_shca *shca,
 					 &eq->length,
 					 &nr_pages, &eq->ist);
 
-	if (ret != H_SUCCESS) {
+	if (h_ret != H_SUCCESS) {
 		ehca_err(ib_dev, "Can't allocate EQ/NEQ. eq=%p", eq);
 		return -EINVAL;
 	}
@@ -97,13 +98,11 @@ int ehca_create_eq(struct ehca_shca *shca,
 		u64 rpage;
 
 		vpage = ipz_qpageit_get_inc(&eq->ipz_queue);
-		if (!vpage) {
-			ret = H_RESOURCE;
+		if (!vpage)
 			goto create_eq_exit2;
-		}
 
 		rpage = virt_to_abs(vpage);
-		ret = hipz_h_register_rpage_eq(shca->ipz_hca_handle,
+		h_ret = hipz_h_register_rpage_eq(shca->ipz_hca_handle,
 						 eq->ipz_eq_handle,
 						 &eq->pf,
 						 0, 0, rpage, 1);
@@ -111,10 +110,10 @@ int ehca_create_eq(struct ehca_shca *shca,
 		if (i == (nr_pages - 1)) {
 			/* last page */
 			vpage = ipz_qpageit_get_inc(&eq->ipz_queue);
-			if (ret != H_SUCCESS || vpage)
+			if (h_ret != H_SUCCESS || vpage)
 				goto create_eq_exit2;
 		} else {
-			if (ret != H_PAGE_REGISTERED || !vpage)
+			if (h_ret != H_PAGE_REGISTERED || !vpage)
 				goto create_eq_exit2;
 		}
 	}