media: solo6x10: simplify the logic at solo_p2m_dma_desc()

The logic with gets a p2m_id is more complex than needed,
causing false positives with static analyzers:

	drivers/media/pci/solo6x10/solo6x10-p2m.c:81 solo_p2m_dma_desc() error: buffer overflow 'solo_dev->p2m_dev' 4 <= s32max

Make it simpler and use unsigned int.
Signed-off-by: NMauro Carvalho Chehab <mchehab@s-opensource.com>

drivers/media/pci/solo6x10/solo6x10-p2m.c

@@ -69,14 +69,11 @@ int solo_p2m_dma_desc(struct solo_dev *solo_dev,
 	unsigned int timeout;
 	unsigned int config = 0;
 	int ret = 0;
-	int p2m_id = 0;
+	unsigned int p2m_id = 0;
 
 	/* Get next ID. According to Softlogic, 6110 has problems on !=0 P2M */
-	if (solo_dev->type != SOLO_DEV_6110 && multi_p2m) {
+	if (solo_dev->type != SOLO_DEV_6110 && multi_p2m)
 		p2m_id = atomic_inc_return(&solo_dev->p2m_count) % SOLO_NR_P2M;
-		if (p2m_id < 0)
-			p2m_id = -p2m_id;
-	}
 
 	p2m_dev = &solo_dev->p2m_dev[p2m_id];