kernel-doc: skip nested struct/union cleanly

Fix handling of nested structs or unions. The regex to strip (eliminate)
nested structs or unions was limited to only 0 or 1 matches. This can
cause an uneven number of left/right braces to be stripped, which causes
this:

Warning(linux-2.6.27-rc1-git2//include/net/mac80211.h:336): No description found for parameter '}'

Signed-off-by: Randy Dunlap <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

scripts/kernel-doc

···
 	my $members = $3;
 
 	# ignore embedded structs or unions
-	$members =~ s/{.*?}//g;
+	$members =~ s/{.*}//g;
 
 	# ignore members marked private:
 	$members =~ s/\/\*.*?private:.*?public:.*?\*\///gos;