checkpatch: fix spello

The plural of parenthesis is parentheses.

Cc: Joe Perches <joe@perches.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/scripts/checkpatch.pl b/scripts/checkpatch.pl
index 4d08b39..4d869dd 100755
--- a/scripts/checkpatch.pl
+++ b/scripts/checkpatch.pl
@@ -4126,7 +4126,7 @@
 					      "Macros with multiple statements should be enclosed in a do - while loop\n" . "$herectx");
 				} else {
 					ERROR("COMPLEX_MACRO",
-					      "Macros with complex values should be enclosed in parenthesis\n" . "$herectx");
+					      "Macros with complex values should be enclosed in parentheses\n" . "$herectx");
 				}
 			}