media: video: Fix build in saa7164

-tip testing found that the x86 build (64-bit allyesconfig) fails due to:

  LD      vmlinux.o
  drivers/built-in.o:(.bss+0x4b648): multiple definition of `debug'
  arch/x86/built-in.o:(.kprobes.text+0x88): first defined here
  ld: Warning: size of symbol `debug' changed from 90 in
arch/x86/built-in.o to 4 in drivers/built-in.o
 make: *** [vmlinux.o] Error 1

This is because recent saa7164 changes introduced a global symbol
named 'debug'. The x86 platform code already defines a 'debug'
symbol. (which is named in a too generic way as well - but it
can be used nicely to weed out too generic symbols in drivers ;-)

Rename it to saa_debug.

[mchehab@redhat.com: use module_param_named to preserve old name]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/saa7164/saa7164-api.c b/drivers/media/video/saa7164/saa7164-api.c
index bb6df1b..6f094a9 100644
--- a/drivers/media/video/saa7164/saa7164-api.c
+++ b/drivers/media/video/saa7164/saa7164-api.c
@@ -415,7 +415,7 @@
 		goto out;
 	}
 
-	if (debug & DBGLVL_API)
+	if (saa_debug & DBGLVL_API)
 		saa7164_dumphex16(dev, buf, (buflen/16)*16);
 
 	saa7164_api_dump_subdevs(dev, buf, buflen);
@@ -480,7 +480,7 @@
 
 	dprintk(DBGLVL_API, "%s() len = %d bytes\n", __func__, len);
 
-	if (debug & DBGLVL_I2C)
+	if (saa_debug & DBGLVL_I2C)
 		saa7164_dumphex16(dev, buf, 2 * 16);
 
 	ret = saa7164_cmd_send(bus->dev, unitid, GET_CUR,
@@ -488,7 +488,7 @@
 	if (ret != SAA_OK)
 		printk(KERN_ERR "%s() error, ret(2) = 0x%x\n", __func__, ret);
 	else {
-		if (debug & DBGLVL_I2C)
+		if (saa_debug & DBGLVL_I2C)
 			saa7164_dumphex16(dev, buf, sizeof(buf));
 		memcpy(data, (buf + 2 * sizeof(u32) + reglen), datalen);
 	}
@@ -548,7 +548,7 @@
 	*((u32 *)(buf + 1 * sizeof(u32))) = datalen - reglen;
 	memcpy((buf + 2 * sizeof(u32)), data, datalen);
 
-	if (debug & DBGLVL_I2C)
+	if (saa_debug & DBGLVL_I2C)
 		saa7164_dumphex16(dev, buf, sizeof(buf));
 
 	ret = saa7164_cmd_send(bus->dev, unitid, SET_CUR,