x86/asm: Have the __ASM_FORM macros handle commas in arguments

The __ASM_FORM macros are really useful, but in order to be able to
use them to define instructions via .byte directives breaks because of
the necessary commas. Change the macros to handle commas correctly.

[ mingo: Removed stray whitespaces & aligned the definitions vertically. ]
Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210510090940.924953-2-hpa@zytor.com

arch/x86/include/asm/asm.h

@@ -3,25 +3,24 @@
 #define _ASM_X86_ASM_H
 
 #ifdef __ASSEMBLY__
-# define __ASM_FORM(x)	x
-# define __ASM_FORM_RAW(x)     x
-# define __ASM_FORM_COMMA(x) x,
+# define __ASM_FORM(x, ...)		x,## __VA_ARGS__
+# define __ASM_FORM_RAW(x, ...)		x,## __VA_ARGS__
+# define __ASM_FORM_COMMA(x, ...)	x,## __VA_ARGS__,
 #else
 #include <linux/stringify.h>
-
-# define __ASM_FORM(x)	" " __stringify(x) " "
-# define __ASM_FORM_RAW(x)     __stringify(x)
-# define __ASM_FORM_COMMA(x) " " __stringify(x) ","
+# define __ASM_FORM(x, ...)		" " __stringify(x,##__VA_ARGS__) " "
+# define __ASM_FORM_RAW(x, ...)		    __stringify(x,##__VA_ARGS__)
+# define __ASM_FORM_COMMA(x, ...)	" " __stringify(x,##__VA_ARGS__) ","
 #endif
 
 #ifndef __x86_64__
 /* 32 bit */
-# define __ASM_SEL(a,b) __ASM_FORM(a)
-# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(a)
+# define __ASM_SEL(a,b)		__ASM_FORM(a)
+# define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(a)
 #else
 /* 64 bit */
-# define __ASM_SEL(a,b) __ASM_FORM(b)
-# define __ASM_SEL_RAW(a,b) __ASM_FORM_RAW(b)
+# define __ASM_SEL(a,b)		__ASM_FORM(b)
+# define __ASM_SEL_RAW(a,b)	__ASM_FORM_RAW(b)
 #endif
 
 #define __ASM_SIZE(inst, ...)	__ASM_SEL(inst##l##__VA_ARGS__, \