[PATCH] ssb-main: Fix division by zero in ssb_calc_clock_rate()

[Rand Deeb <deeb.rand@confident.ru>]

In the line 910, the value of m1 may be zero, so there is a possibility
of dividing by zero, we fixed it by checking the values before dividing
(found with SVACE). In the same way, after checking and reading the
function, we found that lines 906, 908, 912 have the same situation, so
we fixed them as well.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Signed-off-by: Rand Deeb <deeb.rand@confident.ru>
---
 drivers/ssb/main.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/ssb/main.c b/drivers/ssb/main.c
index 0a26984acb2c..e0776a16d04d 100644
--- a/drivers/ssb/main.c
+++ b/drivers/ssb/main.c
@@ -903,13 +903,21 @@ u32 ssb_calc_clock_rate(u32 plltype, u32 n, u32 m)
 		case SSB_CHIPCO_CLK_MC_BYPASS:
 			return clock;
 		case SSB_CHIPCO_CLK_MC_M1:
-			return (clock / m1);
+			if (m1 != 0)
+				return (clock / m1);
+			break;
 		case SSB_CHIPCO_CLK_MC_M1M2:
-			return (clock / (m1 * m2));
+			if ((m1 * m2) != 0)
+				return (clock / (m1 * m2));
+			break;
 		case SSB_CHIPCO_CLK_MC_M1M2M3:
-			return (clock / (m1 * m2 * m3));
+			if ((m1 * m2 * m3) != 0)
+				return (clock / (m1 * m2 * m3));
+			break;
 		case SSB_CHIPCO_CLK_MC_M1M3:
-			return (clock / (m1 * m3));
+			if ((m1 * m3) != 0)
+				return (clock / (m1 * m3));
+			break;
 		}
 		return 0;
 	case SSB_PLLTYPE_2:
-- 
2.34.1