Fix misspellings of "system", "controller", "interrupt" and "necessary".

Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".

Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>

drivers/net/smc911x.c

@@ -1223,7 +1223,7 @@ static irqreturn_t smc911x_interrupt(int irq, void *dev_id)
 		}
 #endif
 
-		/* Handle PHY interupt condition */
+		/* Handle PHY interrupt condition */
 		if (status & INT_STS_PHY_INT_) {
 			DBG(SMC_DEBUG_MISC, "%s: PHY irq\n", dev->name);
 			smc911x_phy_interrupt(dev);