[ARM] arch/arm/common/sa1111.c: Correct error handling code

If it is reasonable to apply PTR_ERR to the result of calling clk_get, then
that result should first be tested with IS_ERR, not with !.

The semantic patch that makes this change is as follows:
(http://www.emn.fr/x-info/coccinelle/)

// <smpl>
@@
expression E,E1;
@@

if (
-   E == NULL
+   IS_ERR(E)
   ) { <+... when != E = E1
        PTR_ERR(E)
       ...+> }
// </smpl>
Signed-off-by: Julia Lawall <julia@diku.dk>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/common/sa1111.c

@@ -630,7 +630,7 @@ __sa1111_probe(struct device *me, struct resource *mem, int irq)
 		return -ENOMEM;
 
 	sachip->clk = clk_get(me, "SA1111_CLK");
-	if (!sachip->clk) {
+	if (IS_ERR(sachip->clk)) {
 		ret = PTR_ERR(sachip->clk);
 		goto err_free;
 	}