checkpatch: allow spaces before parenthesis for 'coroutine_fn'

Signed-off-by: Jeff Cody <jcody@redhat.com>
Message-Id: <83b0fae0728906e18849c971d22d077d7fc0f179.1478010883.git.jcody@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

scripts/checkpatch.pl

@@ -1754,7 +1754,7 @@ sub process {
 			# Ignore those directives where spaces _are_ permitted.
 			if ($name =~ /^(?:
 				if|for|while|switch|return|case|
-				volatile|__volatile__|
+				volatile|__volatile__|coroutine_fn|
 				__attribute__|format|__extension__|
 				asm|__asm__)$/x)
 			{