Fix misspellings of "whether" in comments.

"Whether" is misspelled in various comments across the tree; this
fixes them. No code changes.

Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/arch/powerpc/platforms/powermac/pic.c b/arch/powerpc/platforms/powermac/pic.c
index c4e6305..31036b5 100644
--- a/arch/powerpc/platforms/powermac/pic.c
+++ b/arch/powerpc/platforms/powermac/pic.c
@@ -529,7 +529,7 @@
 void __init pmac_pic_init(void)
 {
 	/* We configure the OF parsing based on our oldworld vs. newworld
-	 * platform type and wether we were booted by BootX.
+	 * platform type and whether we were booted by BootX.
 	 */
 #ifdef CONFIG_PPC32
 	if (!pmac_newworld)