scripts/kernel-doc: fix parsing of function pointers

kernel-doc fails to parse function definitions like the one below

efi_status_t efi_create_event(uint32_t type, efi_uintn_t notify_tpl,
			      void (EFIAPI *notify_function) (
					struct efi_event *event,
					void *context),
			      void *notify_context, efi_guid_t *group,
			      struct efi_event **event)
{

due to the "EFIAPI" attribute preceding the function name.

cf. https://lkml.org/lkml/2018/9/3/1185

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
diff --git a/scripts/kernel-doc b/scripts/kernel-doc
index 3350e49..516cf1d 100755
--- a/scripts/kernel-doc
+++ b/scripts/kernel-doc
@@ -1382,7 +1382,7 @@
 	} elsif ($arg =~ m/\(.+\)\s*\(/) {
 	    # pointer-to-function
 	    $arg =~ tr/#/,/;
-	    $arg =~ m/[^\(]+\(\*?\s*([\w\.]*)\s*\)/;
+	    $arg =~ m/[^\(]+\([\w\s]*\*?\s*([\w\.]*)\s*\)/;
 	    $param = $1;
 	    $type = $arg;
 	    $type =~ s/([^\(]+\(\*?)\s*$param/$1/;