x86/percpu: Avoid sparse warning with cast to named address space

Teach sparse about __seg_fs and __seg_gs named address space
qualifiers to to avoid warnings about unexpected keyword at
the end of cast operator.

Reported-by: kernel test robot <[email protected]>
Acked-by: Luc Van Oostenryck <[email protected]>
Signed-off-by: Uros Bizjak <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Closes: https://lore.kernel.org/oe-kbuild-all/[email protected]/

Author: ubizjak

arch/x86/include/asm/percpu.h

@@ -36,6 +36,11 @@
 
 #ifdef CONFIG_CC_HAS_NAMED_AS
 
+#ifdef __CHECKER__
+#define __seg_gs		__attribute__((address_space(__seg_gs)))
+#define __seg_fs		__attribute__((address_space(__seg_fs)))
+#endif
+
 #ifdef CONFIG_X86_64
 #define __percpu_seg_override	__seg_gs
 #else