dmaengine: pxa_dma: fix debug information

This fixes the following error:
drivers/dma/pxa_dma.c: In function ‘dbg_show_requester_chan’:
drivers/dma/pxa_dma.c:192:2: error: void value not ignored as it ought to be
  pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx);
  ^
drivers/dma/pxa_dma.c:197:8: error: void value not ignored as it ought to be
        !!(drcmr & DRCMR_MAPVLD));
        ^
scripts/Makefile.build:258: recipe for target 'drivers/dma/pxa_dma.o' failed

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>
diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c
index 11290b8..5cb61ce 100644
--- a/drivers/dma/pxa_dma.c
+++ b/drivers/dma/pxa_dma.c
@@ -184,19 +184,18 @@
 
 static int dbg_show_requester_chan(struct seq_file *s, void *p)
 {
-	int pos = 0;
 	struct pxad_phy *phy = s->private;
 	int i;
 	u32 drcmr;
 
-	pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx);
+	seq_printf(s, "DMA channel %d requester :\n", phy->idx);
 	for (i = 0; i < 70; i++) {
 		drcmr = readl_relaxed(phy->base + pxad_drcmr(i));
 		if ((drcmr & DRCMR_CHLNUM) == phy->idx)
-			pos += seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
-					  !!(drcmr & DRCMR_MAPVLD));
+			seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i,
+				   !!(drcmr & DRCMR_MAPVLD));
 	}
-	return pos;
+	return 0;
 }
 
 static inline int dbg_burst_from_dcmd(u32 dcmd)