Fix common misspellings

Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
diff --git a/Documentation/cpu-hotplug.txt b/Documentation/cpu-hotplug.txt
index 45d5a21..a20bfd4 100644
--- a/Documentation/cpu-hotplug.txt
+++ b/Documentation/cpu-hotplug.txt
@@ -196,7 +196,7 @@
 	#To display the current cpu state.
 	#cat /sys/devices/system/cpu/cpuX/online
 
-Q: Why cant i remove CPU0 on some systems?
+Q: Why can't i remove CPU0 on some systems?
 A: Some architectures may have some special dependency on a certain CPU.
 
 For e.g in IA64 platforms we have ability to sent platform interrupts to the