x86/paravirt: Make the struct paravirt_patch_site packed

Similar to struct alt_instr, make the struct paravirt_patch_site packed
and get rid of all the .align directives and save 2 bytes for one
PARA_SITE entry on X86_64.

  [ bp: Massage commit message. ]

Suggested-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Hou Wenlong <houwenlong.hwl@antgroup.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Juergen Gross <jgross@suse.com>
Link: https://lore.kernel.org/r/6dcb20159ded36586c5f7f2ae159e4e030256627.1686301237.git.houwenlong.hwl@antgroup.com

arch/x86/include/asm/paravirt.h

@@ -748,11 +748,9 @@ void native_pv_lock_init(void) __init;
 	ops;					\
 772:;						\
 	.pushsection .parainstructions,"a";	\
-	 .align	4;				\
 	 .long 771b-.;				\
 	 .byte ptype;				\
 	 .byte 772b-771b;			\
-	 .align 4;				\
 	.popsection
 
 

arch/x86/include/asm/paravirt_types.h

@@ -8,7 +8,7 @@ struct paravirt_patch_site {
 	s32 instr_offset;	/* original instructions */
 	u8 type;		/* type of this instruction */
 	u8 len;			/* length of original instruction */
-};
+} __packed;
 #endif
 
 #ifdef CONFIG_PARAVIRT
@@ -263,11 +263,9 @@ extern struct paravirt_patch_template pv_ops;
 #define _paravirt_alt(insn_string, type)		\
 	"771:\n\t" insn_string "\n" "772:\n"		\
 	".pushsection .parainstructions,\"a\"\n"	\
-	"  .align 4\n"					\
 	"  .long 771b-.\n"				\
 	"  .byte " type "\n"				\
 	"  .byte 772b-771b\n"				\
-	"  .align 4\n"					\
 	".popsection\n"
 
 /* Generate patchable code, with the default asm parameters. */