ARM: 6024/1: bcmring: fix missing down on semaphore in dma.c

Added missing down on the memMap->lock semaphore. Also fixed a return
statement so that we always exit with an up (i.e. early exit via return
is not allowed)

Signed-off-by: Leo Hao Chen <[e-mail]>
Signed-off-by: Russell King <[e-mail]>

arch/arm/mach-bcmring/dma.c

···
 int dma_unmap(DMA_MemMap_t *memMap,	/* Stores state information about the map */
 	      int dirtied	/* non-zero if any of the pages were modified */
     ) {
+
+	int rc = 0;
 	int regionIdx;
 	int segmentIdx;
 	DMA_Region_t *region;
 	DMA_Segment_t *segment;
+
+	down(&memMap->lock);
 
 	for (regionIdx = 0; regionIdx < memMap->numRegionsUsed; regionIdx++) {
 		region = &memMap->region[regionIdx];
···
 					printk(KERN_ERR
 					       "%s: vmalloc'd pages are not yet supported\n",
 					       __func__);
-					return -EINVAL;
+					rc = -EINVAL;
+					goto out;
 				}
 
 			case DMA_MEM_TYPE_KMALLOC:
···
 					printk(KERN_ERR
 					       "%s: Unsupported memory type: %d\n",
 					       __func__, region->memType);
-					return -EINVAL;
+					rc = -EINVAL;
+					goto out;
 				}
 			}
 
···
 	memMap->numRegionsUsed = 0;
 	memMap->inUse = 0;
 
+out:
 	up(&memMap->lock);
 
-	return 0;
+	return rc;
 }
 
 EXPORT_SYMBOL(dma_unmap);