x86: Clean up 'sizeof x' => 'sizeof(x)'

"sizeof(x)" is the canonical coding style used in arch/x86 most of the time.
Fix the few places that didn't follow the convention.

(Also do some whitespace cleanups in a few places while at it.)

[ mingo: Rewrote the changelog. ]

Signed-off-by: Jordan Borgner <mail@jordan-borgner.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20181028125828.7rgammkgzep2wpam@JordanDesktop
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/arch/x86/kernel/cpu/mtrr/if.c b/arch/x86/kernel/cpu/mtrr/if.c
index 40eee6c..2e173d4 100644
--- a/arch/x86/kernel/cpu/mtrr/if.c
+++ b/arch/x86/kernel/cpu/mtrr/if.c
@@ -174,12 +174,12 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
 	case MTRRIOC_SET_PAGE_ENTRY:
 	case MTRRIOC_DEL_PAGE_ENTRY:
 	case MTRRIOC_KILL_PAGE_ENTRY:
-		if (copy_from_user(&sentry, arg, sizeof sentry))
+		if (copy_from_user(&sentry, arg, sizeof(sentry)))
 			return -EFAULT;
 		break;
 	case MTRRIOC_GET_ENTRY:
 	case MTRRIOC_GET_PAGE_ENTRY:
-		if (copy_from_user(&gentry, arg, sizeof gentry))
+		if (copy_from_user(&gentry, arg, sizeof(gentry)))
 			return -EFAULT;
 		break;
 #ifdef CONFIG_COMPAT
@@ -332,7 +332,7 @@ mtrr_ioctl(struct file *file, unsigned int cmd, unsigned long __arg)
 	switch (cmd) {
 	case MTRRIOC_GET_ENTRY:
 	case MTRRIOC_GET_PAGE_ENTRY:
-		if (copy_to_user(arg, &gentry, sizeof gentry))
+		if (copy_to_user(arg, &gentry, sizeof(gentry)))
 			err = -EFAULT;
 		break;
 #ifdef CONFIG_COMPAT