doc: fix some typos

Fix some typos in three documentations.

Signed-off-by: Xishi Qiu <qiuxishi@huawei.com>
Acked-by: Rob Landley <rob@landley.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
diff --git a/Documentation/IRQ-domain.txt b/Documentation/IRQ-domain.txt
index 9bc9594..03df71a 100644
--- a/Documentation/IRQ-domain.txt
+++ b/Documentation/IRQ-domain.txt
@@ -141,7 +141,7 @@
 system and will otherwise use a linear domain mapping. The semantics
 of this call are such that if an IRQ range is specified then
 descriptors will be allocated on-the-fly for it, and if no range is
-specified it will fall through to irq_domain_add_linear() which meand
+specified it will fall through to irq_domain_add_linear() which means
 *no* irq descriptors will be allocated.
 
 A typical use case for simple domains is where an irqchip provider