ARM: OMAP2+: remove superfluous NULL pointer check

The NULL pointer check for superset->muxnames will always evaluate
true since muxnames is an array within struct omap_mux. Remove the
superfluous check to avoid warnings when using LLVM/clang.
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Tony Lindgren <tony@atomide.com>

arch/arm/mach-omap2/mux.c

@@ -1053,7 +1053,7 @@ static void __init omap_mux_init_list(struct omap_mux_partition *partition,
 		struct omap_mux *entry;
 
 #ifdef CONFIG_OMAP_MUX
-		if (!superset->muxnames || !superset->muxnames[0]) {
+		if (!superset->muxnames[0]) {
 			superset++;
 			continue;
 		}