x86: rename the struct pt_regs members for 32/64-bit consistency

We have a lot of code which differs only by the naming of specific
members of structures that contain registers.  In order to enable
additional unifications, this patch drops the e- or r- size prefix
from the register names in struct pt_regs, and drops the x- prefixes
for segment registers on the 32-bit side.

This patch also performs the equivalent renames in some additional
places that might be candidates for unification in the future.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c
index 0bf7f20..3566191 100644
--- a/arch/x86/kernel/smpboot_32.c
+++ b/arch/x86/kernel/smpboot_32.c
@@ -447,7 +447,7 @@
 {
 	/*
 	 * We don't actually need to load the full TSS,
-	 * basically just the stack pointer and the eip.
+	 * basically just the stack pointer and the ip.
 	 */
 
 	asm volatile(
@@ -459,7 +459,7 @@
 
 /* Static state in head.S used to set up a CPU */
 extern struct {
-	void * esp;
+	void * sp;
 	unsigned short ss;
 } stack_start;
 
@@ -667,7 +667,7 @@
 	 * target processor state.
 	 */
 	startup_ipi_hook(phys_apicid, (unsigned long) start_secondary,
-		         (unsigned long) stack_start.esp);
+		         (unsigned long) stack_start.sp);
 
 	/*
 	 * Run STARTUP IPI loop.
@@ -806,9 +806,9 @@
 	alternatives_smp_switch(1);
 
 	/* So we see what's up   */
-	printk("Booting processor %d/%d eip %lx\n", cpu, apicid, start_eip);
+	printk("Booting processor %d/%d ip %lx\n", cpu, apicid, start_eip);
 	/* Stack for startup_32 can be just as for start_secondary onwards */
-	stack_start.esp = (void *) idle->thread.esp;
+	stack_start.sp = (void *) idle->thread.esp;
 
 	irq_ctx_init(cpu);