mfd: stmfx: Fix an endian bug in stmfx_irq_handler()

It's not okay to cast a "u32 *" to "unsigned long *" when you are
doing a for_each_set_bit() loop because that will break on big
endian systems.

Fixes: 386145601b82 ("mfd: stmfx: Uninitialized variable in stmfx_irq_handler()")
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>

drivers/mfd/stmfx.c

@@ -204,6 +204,7 @@ static struct irq_chip stmfx_irq_chip = {
 static irqreturn_t stmfx_irq_handler(int irq, void *data)
 {
 	struct stmfx *stmfx = data;
+	unsigned long bits;
 	u32 pending, ack;
 	int n, ret;
 
@@ -222,7 +223,8 @@ static irqreturn_t stmfx_irq_handler(int irq, void *data)
 			return IRQ_NONE;
 	}
 
-	for_each_set_bit(n, (unsigned long *)&pending, STMFX_REG_IRQ_SRC_MAX)
+	bits = pending;
+	for_each_set_bit(n, &bits, STMFX_REG_IRQ_SRC_MAX)
 		handle_nested_irq(irq_find_mapping(stmfx->irq_domain, n));
 
 	return IRQ_HANDLED;