[media] radio-bcm2048.c: Fix some checkpatch.pl errors

Fix the following warnings reported in radio-bcm2048.c:

WARNING: else is not generally useful after a break or return
374: FILE: radio-bcm2048.c:374:
+		return 0;
+	} else {

WARNING: else is not generally useful after a break or return
728: FILE: radio-bcm2048.c:728:
+			return BCM2048_DE_EMPHASIS_75us;
+		else

WARNING: unchecked sscanf return value
1974: FILE: radio-bcm2048.c:1974:
+	sscanf(buf, mask, &value);					\

WARNING: Missing a blank line after declarations
2245: FILE: radio-bcm2048.c:2245:
+		unsigned char tmpbuf[3];
+		tmpbuf[i] = bdev->rds_info.radio_text[bdev->rd_index+i+2];

WARNING: Possible unnecessary 'out of memory' message
2601: FILE: radio-bcm2048.c:2601:
+	if (!bdev) {
+		dev_dbg(&client->dev, "Failed to alloc video device.\n");

The following error was left since it seems to be a false positive:

ERROR: Macros with complex values should be enclosed in parenthesis
+#define DEFINE_SYSFS_PROPERTY(prop, signal, size, mask, check)		\
+property_write(prop, signal size, mask, check)				\
+property_read(prop, size, mask)

Signed-off-by: Luke Hart <luke.hart@birchleys.eu>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>