[MIPS] Alchemy: replace ffs() with __ffs()

Fix havoc wrought by commit 56f621c7f6f735311eed3f36858b402013023c18 --
au_ffs() and ffs() are equivalent, that patch should have just replaced one
with another.  Now replace ffs() with __ffs() which returns an unbiased bit
number.

Signed-off-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/au1000/common/irq.c b/arch/mips/au1000/common/irq.c
index ddfb7f0..b7f1bbf 100644
--- a/arch/mips/au1000/common/irq.c
+++ b/arch/mips/au1000/common/irq.c
@@ -462,7 +462,7 @@
 		return;
 	}
 #endif
-	bit = ffs(intc0_req0);
+	bit = __ffs(intc0_req0);
 	intc0_req0 &= ~(1 << bit);
 	do_IRQ(MIPS_CPU_IRQ_BASE + bit);
 }
@@ -478,7 +478,7 @@
 	if (!intc0_req1)
 		return;
 
-	bit = ffs(intc0_req1);
+	bit = __ffs(intc0_req1);
 	intc0_req1 &= ~(1 << bit);
 	do_IRQ(bit);
 }
@@ -498,7 +498,7 @@
 	if (!intc1_req0)
 		return;
 
-	bit = ffs(intc1_req0);
+	bit = __ffs(intc1_req0);
 	intc1_req0 &= ~(1 << bit);
 	do_IRQ(MIPS_CPU_IRQ_BASE + 32 + bit);
 }
@@ -514,7 +514,7 @@
 	if (!intc1_req1)
 		return;
 
-	bit = ffs(intc1_req1);
+	bit = __ffs(intc1_req1);
 	intc1_req1 &= ~(1 << bit);
 	do_IRQ(MIPS_CPU_IRQ_BASE + 32 + bit);
 }