fbcon: replace mono_col macro with static inline

Use __u32 for max_len to match the declaration of length in the struct
fb_bitfield.

Suppresses sparse shadowed variable warnings from the nested max()
macros:
drivers/video/console/fbcon.h:130:8: warning: symbol '_x' shadows an earlier one
drivers/video/console/fbcon.h:130:8: originally declared here
drivers/video/console/fbcon.h:130:8: warning: symbol '_x' shadows an earlier one
drivers/video/console/fbcon.h:130:8: originally declared here
drivers/video/console/fbcon.h:130:8: warning: symbol '_y' shadows an earlier one
drivers/video/console/fbcon.h:130:8: originally declared here

[akpm@linux-foundation.org: fix constness]
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/video/console/fbcon.h

@@ -104,10 +104,14 @@ struct fbcon_ops {
 #define attr_blink(s) \
 	((s) & 0x8000)
 
-#define mono_col(info)							\
-	(~(0xfff << (max((info)->var.green.length,			\
-			 max((info)->var.red.length,			\
-			     (info)->var.blue.length)))) & 0xff)
+
+static inline int mono_col(const struct fb_info *info)
+{
+	__u32 max_len;
+	max_len = max(info->var.green.length, info->var.red.length);
+	max_len = max(info->var.blue.length, max_len);
+	return ~(0xfff << (max_len & 0xff));
+}
 
 static inline int attr_col_ec(int shift, struct vc_data *vc,
 			      struct fb_info *info, int is_fg)