fsldma: clean up the OF subsystem routines

This fixes some errors in the cleanup paths of the OF subsystem, including
missing checks for ioremap failing. Also, some variables were renamed for
brevity.
Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

drivers/dma/fsldma.h

@@ -108,7 +108,7 @@ struct fsldma_chan;
 #define FSL_DMA_MAX_CHANS_PER_DEVICE 4
 
 struct fsldma_device {
-	void __iomem *reg_base;	/* DGSR register base */
+	void __iomem *regs;	/* DGSR register base */
 	struct device *dev;
 	struct dma_device common;
 	struct fsldma_chan *chan[FSL_DMA_MAX_CHANS_PER_DEVICE];
@@ -128,7 +128,7 @@ struct fsldma_device {
 #define FSL_DMA_CHAN_START_EXT	0x00002000
 
 struct fsldma_chan {
-	struct fsldma_chan_regs __iomem *reg_base;
+	struct fsldma_chan_regs __iomem *regs;
 	dma_cookie_t completed_cookie;	/* The maximum cookie completed */
 	spinlock_t desc_lock;		/* Descriptor operation lock */
 	struct list_head ld_queue;	/* Link descriptors queue */